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Bakin karfe da ake amfani da shi sosai da kuma nau'ikan da aka ƙera suna da juriya ga tsatsa a yanayin yanayi saboda layin passivation wanda ya ƙunshi chromium oxide. Tsatsa da lalacewar ƙarfe a al'ada suna da alaƙa da lalata waɗannan yadudduka, amma ba kasafai suke a matakin ƙananan ba, ya danganta da asalin rashin daidaituwar saman. A cikin wannan aikin, bambancin sinadarai na saman nanoscale da aka gano ta hanyar nanoscope da nazarin chemometric ba zato ba tsammani ya mamaye rugujewa da tsatsa na cerium modified super duplex bakin karfe 2507 (SDSS) mai sanyi a lokacin yanayin lalacewarsa mai zafi. a gefe guda. Kodayake na'urar daukar hoto ta X-ray photoelectron ta nuna cikakken rufewar layin Cr2O3 na halitta iri ɗaya, SDSS mai sanyi da aka ƙera ya nuna mummunan sakamakon passivation saboda rarraba tsibirin nano mai arziki na Fe3+ a kan layin oxide na Fe/Cr. Wannan ilimin a matakin atomic yana ba da zurfin fahimtar tsatsa na bakin karfe kuma ana sa ran zai taimaka wajen yaƙi da tsatsa na irin waɗannan ƙarfe masu ƙarfi.
Tun lokacin da aka ƙirƙiro ƙarfe mai bakin ƙarfe, an danganta juriyar tsatsa ta ƙarfe ferrochromium ga chromium, wanda ke samar da ƙarfin oxide/oxyhydroxide wanda ke nuna halayen passivating a yawancin muhalli. Idan aka kwatanta da ƙarfe na gargajiya (austenitic da ferritic), ƙarfe mai ƙarfi duplex mai juriyar tsatsa suna da kyawawan halaye na injiniya1,2,3. Ƙarfin injina yana ba da damar ƙira mai sauƙi da ƙanƙanta. Sabanin haka, SDSS mai tattalin arziki yana da juriya mai ƙarfi ga tsatsa da tsatsa mai ƙwanƙwasa, wanda ke haifar da tsawon rai na sabis da aikace-aikace masu faɗi a cikin sarrafa gurɓataccen iska, kwantena na sinadarai, da masana'antar mai da iskar gas ta teku4. Duk da haka, kunkuntar yanayin zafi na maganin zafi da rashin kyawun tsari yana hana amfani da shi mai yawa. Saboda haka, an gyara SDSS don inganta halayen da ke sama. Misali, an gabatar da gyare-gyaren Ce da ƙarin N 6, 7, 8 a cikin 2507 SDSS (Ce-2507). Daidaitaccen yawan sinadarin ƙasa mai nauyin 0.08 wt.% (Ce) yana da tasiri mai kyau akan halayen injina na DSS, domin yana inganta tsaftace hatsi da ƙarfin iyakokin hatsi. An kuma inganta juriyar lalacewa da tsatsa, ƙarfin tauri da ƙarfin samarwa, da kuma sauƙin aiki mai zafi9. Yawan nitrogen na iya maye gurbin sinadarin nickel mai tsada, wanda hakan ke sa SDSS ya fi araha10.
Kwanan nan, SDSS ta lalace ta hanyar filastik a yanayin zafi daban-daban (ƙananan zafin jiki, sanyi da zafi) don cimma kyawawan halayen injiniya6,7,8. Duk da haka, kyakkyawan juriyar tsatsa na SDSS ya faru ne saboda kasancewar wani siririn fim ɗin oxide a saman, wanda ke shafar abubuwa da yawa, kamar kasancewar matakai da yawa tare da iyakokin hatsi daban-daban, abubuwan da ba a so da kuma halayen daban-daban. Tsarin ciki mara daidaituwa na matakai daban-daban na austenitic da ferritic ya lalace 7. Saboda haka, nazarin halayen ƙananan yankuna na irin waɗannan fina-finai a matakin tsarin lantarki yana da matukar muhimmanci don fahimtar tsatsa na SDSS kuma yana buƙatar dabarun gwaji masu rikitarwa. Zuwa yanzu, hanyoyin da ke da alaƙa da saman kamar Auger electron spectroscopy11 da X-ray photoelectron spectroscopy12,13,14,15 da kuma tsarin X-ray photoelectron mai tauri suna bambanta, amma galibi ba sa rabuwa, yanayin sinadarai na abu ɗaya a wurare daban-daban a sararin samaniya akan sikelin nano. Nazarce-nazarce da dama da aka yi kwanan nan sun danganta iskar shaka ta chromium ta gida da halayen tsatsa da aka lura da su na ƙarfe 17 na austenitic bakin ƙarfe, ƙarfe 18 na martensitic bakin ƙarfe, da SDSS 19, 20. Duk da haka, waɗannan nazarin sun fi mayar da hankali kan tasirin bambancin Cr (misali, yanayin oxidation na Cr3+) akan juriyar tsatsa. Bambancin gefe a cikin yanayin oxidation na abubuwa na iya faruwa ta hanyar mahaɗan daban-daban tare da abubuwan da ke cikin guda ɗaya, kamar ƙarfe oxides. Waɗannan mahaɗan suna gadar ƙaramin girman da aka sarrafa ta hanyar thermomechanical kusa da juna, amma sun bambanta a cikin abun da ke ciki da yanayin oxidation16,21. Saboda haka, bayyana lalata fina-finan oxide sannan a cire su yana buƙatar fahimtar rashin daidaituwar saman a matakin microscopic. Duk da waɗannan buƙatun, kimantawa na adadi kamar bambancin oxidation na gefe, musamman na ƙarfe akan sikelin nano/atomic, har yanzu ba a gano su ba kuma mahimmancin su ga juriyar tsatsa har yanzu ba a bincika su ba. Har zuwa kwanan nan, an bayyana yanayin sinadarai na abubuwa daban-daban, kamar Fe da Ca, a kan samfuran ƙarfe ta amfani da na'urar hangen nesa ta X-ray mai laushi (X-PEEM) a cikin wuraren hasken nanoscale synchrotron. Idan aka haɗa shi da dabarun X-ray absorption spectroscopy (XAS) masu saurin kamuwa da sinadarai, X-PEEM yana ba da damar auna XAS tare da ƙudurin sarari da na spectral mai girma, yana ba da bayanai game da sinadarai game da abubuwan da ke cikin sinadarai da yanayin sinadarai tare da ƙudurin sarari har zuwa sikelin nanometer 23. Wannan lura da wurin farawa a ƙarƙashin na'urar hangen nesa yana sauƙaƙa gwaje-gwajen sinadarai na gida kuma yana iya nuna canje-canjen sinadarai da ba a bincika ba a baya a cikin layin Fe.
Wannan binciken ya faɗaɗa fa'idodin PEEM wajen gano bambance-bambancen sinadarai a sikelin nano kuma ya gabatar da wata hanyar nazarin saman matakin atomic mai zurfi don fahimtar halayen lalata na Ce-2507. Yana amfani da bayanan kemometric na rukuni na K24 don zana taswirar abubuwan da ke cikin sinadarai na duniya (bambancin) na abubuwan da ke cikin, tare da gabatar da yanayin sinadarai a cikin wakilcin ƙididdiga. Ba kamar yanayin gargajiya na lalata da ke faruwa sakamakon lalacewar fim ɗin chromium oxide ba, rashin kyawun passivation na yanzu da rashin juriyar tsatsa ana danganta su da tsibiran nano masu arziki na Fe3+ kusa da layin oxide na Fe/Cr, wanda zai iya zama sakamakon oxides masu kariya. A wurin rushewa, ana samar da fim wanda ke haifar da tsatsa.
An fara kimanta halayen lalata na nakasassu SDSS 2507 ta amfani da ma'aunin lantarki. A hoto na 1 yana nuna lanƙwasa na Nyquist da Bode don samfuran da aka zaɓa a cikin ruwan acidic (pH = 1) na FeCl3 a zafin ɗaki. Zaɓaɓɓen electrolyte yana aiki azaman mai ƙarfi na oxidizing, yana nuna yanayin da fim ɗin passivation ke wargajewa. Kodayake kayan bai yi riƙon zafin ɗaki mai ɗorewa ba, waɗannan nazarin sun ba da haske game da yiwuwar abubuwan da suka faru na gazawa da hanyoyin bayan lalata. An yi amfani da da'irar daidai (Hoto na 1d) don dacewa da spectra na electrochemical impedance spectroscopy (EIS), kuma an nuna sakamakon daidaitawa masu dacewa a cikin Tebur 1. Rabin da'irori marasa cikawa sun bayyana lokacin gwada samfurin da aka yi wa magani da zafi, yayin da rabin da'irori masu matsewa aka yi birgima da sanyi (Hoto na 1b). A cikin bakan EIS, ana iya ɗaukar radius na rabin da'ira a matsayin juriyar polarization (Rp)25,26. Rp na maganin SDSS da aka yi wa magani a cikin Tebur 1 yana da kusan 135 kΩ cm-2, duk da haka ga SDSS da aka yi wa aiki mai zafi da sanyi da aka yi birgima za mu iya ganin ƙananan ƙima na 34.7 da 2.1 kΩ cm–2 bi da bi. Wannan raguwa mai mahimmanci a cikin Rp yana nuna mummunan tasirin nakasar filastik akan juriyar wucewa da tsatsa, kamar yadda aka nuna a cikin rahotannin da suka gabata 27, 28, 29, 30.
zane-zanen Nyquist, b, c na Bode impedance da phase impedance, da kuma samfurin da'ira mai daidaitacce don d, inda RS shine juriyar electrolyte, Rp shine juriyar polarization, kuma QCPE shine oxide na lokaci mai ɗorewa da ake amfani da shi don yin ƙirar ƙarfin da ba shi da kyau (n). An gudanar da ma'aunin EIS ba tare da ƙarfin kaya ba.
An nuna ma'aunin tsari na farko a cikin zane na Bode kuma babban matakin mitar yana wakiltar juriyar electrolyte RS26. Yayin da mitar ke raguwa, impedance yana ƙaruwa kuma an sami kusurwar mataki mara kyau, yana nuna rinjayen capacitance. Kusurwar mataki tana ƙaruwa, tana riƙe da ƙimarta a cikin kewayon mita mai faɗi, sannan ta ragu (Hoto na 1c). Duk da haka, a cikin dukkan shari'o'i uku wannan matsakaicin ƙimar har yanzu ƙasa da 90°, yana nuna halayen capacitive mara kyau saboda watsawar capacitive. Don haka, ana amfani da sinadarin lokaci na QCPE (CPE) don wakiltar rarrabawar capacitance tsakanin fuska da aka samo daga ƙaiƙayi ko rashin daidaituwa, musamman dangane da sikelin atomic, geometry fractal, electrode porosity, non-uniform potential, da kuma rarrabawar yanzu da ke dogara da saman. Geometry na electrode31,32. CPE impedance:
inda j shine lambar tunani kuma ω shine mitar kusurwa. QCPE shine daidaitaccen mita wanda ya dace da yankin buɗewa mai aiki na electrolyte. n lambar ƙarfi ce mara girma wacce ke bayyana karkacewa daga yanayin capacitor mai kyau, watau kusantar n zuwa 1, kusancin CPE da cikakken capacitance, kuma idan n kusa da sifili, juriya ce. Ƙaramin karkacewa na n, kusa da 1, yana nuna halayen capacitive mara kyau na saman bayan gwajin polarization. QCPE na SDSS mai sanyi ya fi samfuran iri ɗaya girma, wanda ke nufin cewa ingancin saman bai yi kama da juna ba.
Daidai da yawancin halayen juriya ga tsatsa na ƙarfen bakin ƙarfe, yawan Cr da ke cikin SDSS gabaɗaya yana haifar da juriya ga tsatsa na SDSS saboda kasancewar fim ɗin kariya mai wucewa akan saman17. Wannan fim ɗin wucewa yawanci yana da wadataccen oxides na Cr3+ da/ko hydroxides, galibi yana haɗa Fe2+, Fe3+ oxides da/ko (oxy) hydroxides 33. Duk da daidaiton saman iri ɗaya, layin oxide mai wucewa, kuma babu karyewar da ake gani a saman, kamar yadda aka ƙaddara ta hanyar hotuna masu ƙananan bayanai,6,7 halayen tsatsa na SDSS mai zafi da sanyi ya bambanta kuma saboda haka yana buƙatar zurfafa bincike kan tsarin nakasa da halayyar tsarin ƙarfe.
An yi binciken ƙananan tsarin ƙarfe mara kyau ta hanyar amfani da hasken X-ray na ciki da na synchrotron masu ƙarfi (Karin Figures 1, 2). An bayar da cikakken bincike a cikin Ƙarin Bayani. Kodayake wannan galibi ya yi daidai da nau'in babban matakin, an sami bambance-bambance a cikin ɓangarorin girma na matakan, waɗanda aka jera a cikin Tebur na Ƙarin 1. Bambancin na iya kasancewa saboda ɓangaren lokaci daban-daban a saman da kuma ɓangaren girma (XRD) wanda ke ƙarƙashin zurfin ganowa daban-daban ta amfani da bambancin X-ray tare da hanyoyin makamashi daban-daban na photons na abin da ya faru. Mafi girman rabo na austenite a cikin samfuran sanyi da aka birgima, wanda XRD ya ƙaddara daga tushen dakin gwaje-gwaje, yana nuna mafi kyawun passivation da kuma mafi kyawun juriya ga tsatsa35, yayin da sakamakon da ya fi daidai da ƙididdiga ke nuna akasin haka a cikin rabon lokaci. Bugu da ƙari, juriyar tsatsa na ƙarfe kuma ya dogara da matakin tsaftace hatsi, rage girman hatsi, ƙaruwa a cikin ƙananan nakasa da yawan katsewa da ke faruwa yayin maganin thermomechanical36,37,38. Samfuran da aka yi amfani da su a zafi suna nuna yanayin hatsi mai kama da micron, yayin da zoben santsi da aka gani a cikin samfuran da aka yi amfani da su a cikin sanyi (Hoto na 3) suna nuna ingantaccen gyaran hatsi ga nanoscale a cikin aikin da ya gabata na 6, wanda ya kamata ya ba da gudummawa ga samuwar fim da ƙaruwar juriyar tsatsa. Yawancin lokaci yawan nakasa yana da alaƙa da ƙarancin juriya ga rami, wanda ya yi daidai da ma'aunin lantarki.
An yi nazari kan canje-canje a yanayin sinadarai na ƙananan yankuna na abubuwan farko ta amfani da X-PEEM. Duk da yawan abubuwan da ke haɗa sinadarai, an zaɓi Cr, Fe, Ni, da Ce39 a nan saboda Cr shine babban abin da ke samar da fim ɗin passivation, Fe shine babban abin da ke cikin ƙarfe, kuma Ni yana haɓaka passivation kuma yana daidaita tsarin ferrite-austenitic da manufar gyara Ce. Ta hanyar daidaita kuzarin hasken synchrotron, an rufe RAS daga saman tare da manyan fasalulluka na Cr (gefen ​​L2.3), Fe (gefen ​​L2.3), Ni (gefen ​​L2.3) da Ce (gefen M4.5). ƙirƙirar zafi da birgima mai sanyi Ce-2507 SDSS. An gudanar da nazarin bayanai masu dacewa ta hanyar haɗa daidaiton makamashi tare da bayanan da aka buga (misali XAS 40, 41 akan Fe L2, gefen 3).
A kan hoto na 2 yana nuna hotunan X-PEEM na aikin zafi (Hoto na 2a) da na'urar birgima mai sanyi (Hoto na 2d) Ce-2507 SDSS da gefunan XAS masu dacewa na Cr da Fe L2,3 a wurare daban-daban da aka yiwa alama. Gefen L2,3 na XAS yana bincika yanayin 3d mara mamaye bayan fitowar hasken lantarki a matakan raba-zuwa-zuwa-juyawa 2p3/2 (gefen L3) da 2p1/2 (gefen L2). An samo bayanai game da yanayin valence na Cr daga XAS a gefen L2,3 a cikin Hoto na 2b, e. Kwatanta da alƙalai. 42,43 ya nuna cewa an lura da kololuwa huɗu kusa da gefen L3, mai suna A (578.3 eV), B (579.5 eV), C (580.4 eV) da D (582.2 eV), suna nuna octahedral Cr3+, wanda ya dace da ion na Cr2O3. Gwajin da aka yi ya yi daidai da lissafin ka'idar da aka nuna a cikin allunan b da e, waɗanda aka samo daga lissafi da yawa na filin lu'ulu'u a mahaɗin Cr L2.3 ta amfani da filin lu'ulu'u na 2.0 eV44. Duk saman SDSS mai zafi da na sanyi an shafa su da wani Layer na Cr2O3 iri ɗaya.
Hoton zafi na X-PEEM na SDSS mai nakasa a yanayin zafi wanda ya yi daidai da gefen b Cr L2.3 da gefen c Fe L2.3, d hoton zafi na X-PEEM na SDSS mai sanyi wanda ya yi daidai da gefen e Cr L2.3 da gefen f Fe L2 .3 (f). An zana hotunan XAS a wurare daban-daban da aka yiwa alama a kan hotunan zafi (a, d), layukan lemu masu dige-dige a cikin (b) da (e) suna wakiltar hotunan XAS da aka kwaikwayi na Cr3+ tare da ƙimar filin lu'ulu'u na 2.0 eV. Don hotunan X-PEEM, yi amfani da palet ɗin zafi don inganta iya karanta hoto, inda launuka daga shuɗi zuwa ja suke daidai da ƙarfin shan X-ray (daga ƙasa zuwa sama).
Ko da kuwa yanayin sinadarai na waɗannan abubuwan ƙarfe, yanayin sinadarai na ƙarin abubuwan haɗin Ni da Ce don samfuran biyu bai canza ba. Ƙarin zane. Hotuna na 5-9 suna nuna hotunan X-PEEM da kuma spectra XAS masu dacewa don Ni da Ce a wurare daban-daban akan saman samfuran da aka yi amfani da su da zafi da sanyi. Ni XAS yana nuna yanayin iskar shaka na Ni2+ akan dukkan saman da aka auna na samfuran da aka yi amfani da su da zafi da sanyi (Tattaunawa ta Ƙarin). Ya kamata a lura cewa, a yanayin samfuran da aka yi amfani da su da zafi, ba a lura da siginar XAS na Ce ba, yayin da a yanayin samfuran da aka yi amfani da su da sanyi, an lura da bakan Ce3+. Lura da tabo na Ce a cikin samfuran da aka yi amfani da su da sanyi ya nuna cewa Ce galibi yana bayyana ne a cikin nau'in hazo.
A cikin SDSS mai nakasa ta yanayin zafi, ba a ga wani canji na tsarin gida a XAS a gefen Fe L2,3 ba (Hoto na 2c). Duk da haka, matrix na Fe micro-yanki yana canza yanayin sinadaransa a wurare bakwai da aka zaɓa bazuwar SDSS mai sanyi, kamar yadda aka nuna a Hoto na 2f. Bugu da ƙari, don samun cikakken ra'ayi game da canje-canje a yanayin Fe a wurare da aka zaɓa a Hoto na 2f, an gudanar da nazarin saman gida (Hoto na 3 da Hoto na Ƙarin 10) inda aka zaɓi ƙananan yankuna masu zagaye. An yi kwaikwayon XAS na gefen Fe L2,3 na tsarin α-Fe2O3 da Fe2+ octahedral oxides ta hanyar lissafin filin lu'ulu'u da yawa ta amfani da filayen lu'ulu'u na 1.0 (Fe2+) da 1.0 (Fe3+)44. Mun lura cewa α-Fe2O3 da γ-Fe2O3 suna da daidaitattun daidaito na gida45,46, Fe3O4 yana da haɗin Fe2+ da Fe3+,47, da FeO45 a matsayin oxide mai divalent na Fe2+ (3d6). Mun lura cewa α-Fe2O3 da γ-Fe2O3 suna da daidaitattun daidaito na gida45,46, Fe3O4 yana da haɗin Fe2+ da Fe3+,47, da FeO45 a matsayin oxide mai divalent na Fe2+ (3d6).Lura cewa α-Fe2O3 da γ-Fe2O3 suna da daidaitattun daidaito na gida45,46, Fe3O4 ya haɗa duka Fe2+ da Fe3+,47 da FeO45 a cikin nau'in oxide mai divalent Fe2+ (3d6).Lura cewa α-Fe2O3 da γ-Fe2O3 suna da daidaitattun daidaito na gida45,46, Fe3O4 yana da haɗin Fe2+ da Fe3+,47 kuma FeO45 yana aiki azaman divalent Fe2+ oxide (3d6). Duk ions na Fe3+ a cikin α-Fe2O3 suna da matsayi na Oh kawai, yayin da γ-Fe2O3 yawanci ana wakilta shi da Fe3+ t2g [Fe3+5/3V1/3] misali O4 spinel tare da guraben aiki a cikin misalan matsayi. Saboda haka, ions na Fe3+ a cikin γ-Fe2O3 suna da matsayi na Td da Oh. Kamar yadda aka ambata a cikin takarda da ta gabata,45 kodayake rabon ƙarfi na biyu ya bambanta, rabon ƙarfi na su misali/t2g shine ≈1, yayin da a wannan yanayin rabon ƙarfi da aka lura misali/t2g shine kusan 1. Wannan ya kawar da yuwuwar cewa a halin yanzu Fe3+ kawai yake akwai. Idan aka yi la'akari da yanayin Fe3O4 tare da duka Fe2+ da Fe3+, fasalin farko, wanda aka san yana da rauni (ƙarfi) gefen L3 na Fe, yana nuna ƙaramin adadin (mafi girma) na yanayin t2g mara mamaye. Wannan ya shafi Fe2+ (Fe3+), wanda ke nuna cewa fasalin farko na ƙaruwar yana nuna ƙaruwa a cikin abun ciki na Fe2+47. Waɗannan sakamakon sun nuna cewa kasancewar Fe2+ da γ-Fe2O3, α-Fe2O3 da/ko Fe3O4 suna mamaye saman da aka yi birgima da sanyi na mahaɗan.
An faɗaɗa hotunan hotunan zafi na photoelectron na XAS spectra (a, c) da (b, d) suna ketare gefen Fe L2,3 a wurare daban-daban a cikin yankuna da aka zaɓa 2 da E a cikin Fig. 2d.
An zana bayanan gwaji da aka samu (Hoto na 4a da Hoto na Ƙarin 11) kuma an kwatanta su da bayanan mahaɗan tsarki 40, 41, 48. Nau'o'i uku daban-daban na Fe L-gefen XAS da aka lura da gwaji (XAS-1, XAS-2 da XAS-3: Hoto na 4a). Musamman, an lura da bakan 2-a (wanda aka nuna a matsayin XAS-1) a cikin Hoto na 3b tare da bakan 2-b (wanda aka yiwa alama da XAS-2) a duk faɗin yankin ganowa, yayin da aka lura da bakan kamar E-3 a cikin hoto na 3d (wanda aka yiwa alama da XAS-3) a takamaiman wurare. A matsayinka na doka, an yi amfani da sigogi huɗu don gano yanayin valence da ke akwai a cikin samfurin da ke ƙarƙashin binciken: (1) halayen bakan L3 da L2, (2) matsayin kuzari na halaye L3 da L2, (3) bambancin kuzari L3-L2. , (4) rabon ƙarfi L2/L3. A bisa ga abubuwan da aka gani a gani (Hoto na 4a), dukkan sassan Fe guda uku, wato, Fe0, Fe2+, da Fe3+, suna nan a saman SDSS da ake nazari a kai. Rabon ƙarfin da aka ƙididdige L2/L3 shi ma ya nuna kasancewar dukkan sassan uku.
a Siffar XAS da aka Kwaikwayi ta Fe tare da bayanai uku na gwaji daban-daban da aka lura (layukan ƙarfi XAS-1, XAS-2 da XAS-3 sun yi daidai da 2-a, 2-b da E-3 a Hoto na 2 da 3) Kwatanta, Octahedrons Fe2+, Fe3+ tare da ƙimar filin lu'ulu'u na 1.0 eV da 1.5 eV, bi da bi, bayanan gwaji da aka auna da bd (XAS-1, XAS-2, XAS-3) da bayanan LCF da aka inganta (layin baƙi mai ƙarfi), da kuma a cikin nau'in siffar XAS-3 tare da ma'aunin Fe3O4 (yanayin gauraye na Fe) da Fe2O3 (tsarin Fe3+).
An yi amfani da daidaitaccen haɗin kai (LCF) na ma'auni uku 40, 41, 48 don auna yawan sinadarin ƙarfe. An aiwatar da LCF don zaɓaɓɓun siffofi uku na Fe L-edge XAS waɗanda ke nuna mafi girman bambanci, wato XAS-1, XAS-2 da XAS-3, kamar yadda aka nuna a Hoto na 4b-d. Ga kayan haɗin LCF, an yi la'akari da kashi 10% na Fe0 a duk lokuta saboda gaskiyar cewa mun lura da ƙaramin layi a cikin duk bayanai, kuma saboda gaskiyar cewa ƙarfe na ƙarfe shine babban ɓangaren ƙarfe. Hakika, zurfin gwajin X-PEEM don Fe (~6 nm)49 ya fi girma fiye da kauri na Layer oxidation da aka kiyasta (dan kadan fiye da 4 nm), wanda ke ba da damar gano sigina daga matrix na ƙarfe (Fe0) a ƙarƙashin layin wucewa. Hakika, zurfin gwajin X-PEEM don Fe (~6 nm)49 ya fi girma fiye da kauri na Layer oxidation da aka kiyasta (dan kadan fiye da 4 nm), wanda ke ba da damar gano sigina daga matrix na ƙarfe (Fe0) a ƙarƙashin layin wucewa. Действительно, пробная глубина X-PEEM для Fe (~ 6 нм) 49 больше, чем предполагаемая толщина слоя окислоя окислоя позволяет обнаружить сигнал от железной матрицы (Fe0) под пассивирующим слоем. Hakika, zurfin binciken X-PEEM na Fe (~6 nm)49 ya fi kauri da ake tsammani na Layer oxidation (dan kadan fiye da 4 nm), wanda hakan ke sa ya yiwu a gano siginar daga matrix na ƙarfe (Fe0) a ƙarƙashin Layer passivation.事实上，X-PEEM 对Fe（~6 nm）49 的检测深度大于估计的氧化层厚度（略> 4 nm）允许检测来自钝化层下方的铁基体（Fe0）的信号。事实上 ， X-PEEM 对 Fe (~ 6 nm） 49 的 检测 深度 大于钝化层 下方 铁基体 （fe0） 信号 信号 信号 信号 信号信号Фактически, глубина обнаружения Fe (~ 6 нм) 49 с помощью X-PEEM больше > 4 нм), что позволяет обнаруживать сигнал от железной матрицы (Fe0) ниже пассивирующего слоя. A zahiri, zurfin gano Fe (~6 nm) 49 ta hanyar X-PEEM ya fi kauri da ake tsammani na layin oxide (dan kadan fiye da 4 nm), wanda ke ba da damar gano siginar daga matrix na ƙarfe (Fe0) a ƙarƙashin layin passivation. .An yi amfani da nau'ikan haɗuwa iri-iri na Fe2+ da Fe3+ don nemo mafi kyawun mafita ga bayanan gwaji da aka lura. A hoto na 4b yana nuna bakan XAS-1 don haɗakar Fe2+ da Fe3+, inda rabon Fe2+ da Fe3+ suka yi kama da kusan 45%, wanda ke nuna yanayin iskar shaka na Fe. Yayin da ga bakan XAS-2, kashi na Fe2+ da Fe3+ ya zama ~30% da 60%, bi da bi. Fe2+ ​​ya ƙasa da Fe3+. Rabon Fe2+ zuwa Fe3, daidai yake da 1:2, yana nufin cewa ana iya samar da Fe3O4 a daidai rabo tsakanin ions na Fe. Bugu da ƙari, ga bakan XAS-3, kashi na Fe2+ da Fe3+ ya zama ~10% da 80%, wanda ke nuna babban canji na Fe2+ zuwa Fe3+. Kamar yadda aka ambata a sama, Fe3+ na iya fitowa daga α-Fe2O3, γ-Fe2O3 ko Fe3O4. Domin fahimtar tushen da ya fi yiwuwa na Fe3+, an zana bakan XAS-3 tare da ma'aunin Fe3+ daban-daban a cikin Hoto na 4e, wanda ke nuna kamanceceniya da ma'aunin biyu lokacin da ake la'akari da kololuwar B. Duk da haka, ƙarfin kololuwar kafada (A: daga Fe2+) da rabon ƙarfin B/A sun nuna cewa bakan XAS-3 yana kusa, amma bai yi daidai da bakan γ-Fe2O3 ba. Idan aka kwatanta da babban γ-Fe2O3, kololuwar Fe 2p XAS na A SDSS yana da ɗan ƙarfi mafi girma (Hoto na 4e), wanda ke nuna ƙarin ƙarfi na Fe2+. Kodayake bakan XAS-3 yayi kama da na γ-Fe2O3, inda Fe3+ yake a cikin matsayin Oh da Td, gano yanayin valence daban-daban da daidaitawa kawai tare da gefen L2,3 ko rabon ƙarfin L2/L3 ya kasance matsala. batu na tattaunawa mai gudana saboda sarkakiyar abubuwan da ke shafar bakan ƙarshe41.
Baya ga bambance-bambancen spectral a yanayin sinadarai na yankunan da aka zaɓa da aka bayyana a sama, an kuma tantance bambancin sinadarai na duniya na muhimman abubuwan Cr da Fe ta hanyar rarraba dukkan spectra na XAS da aka samu a saman samfurin ta amfani da hanyar haɗa K-means. . Bayanan gefe Cr L an saita su don samar da ƙungiyoyi biyu mafi kyau waɗanda aka rarraba a sarari a cikin samfuran da aka yi amfani da zafi da sanyi da aka nuna a cikin Hoto na 5. A bayyane yake cewa babu wani canje-canje na tsarin gida da ake ɗauka iri ɗaya ne, tunda centroids biyu na spectra na XAS Cr suna kama da juna. Waɗannan siffofi na spectral na clusters biyu kusan iri ɗaya ne da waɗanda suka yi daidai da Cr2O342, wanda ke nufin cewa yadudduka na Cr2O3 suna da daidaito a kan SDSS.
Cr L K-na nufin gungu na yanki na gefen, kuma b shine centroids na XAS masu dacewa. Sakamakon kwatancen K-na nufin X-PEEM na SDSS mai sanyi-birgima: c Cr Yankin gefen L2.3 na gungu na K-na nufin da centroids na XAS masu dacewa.
Domin kwatanta taswirar gefen FeL masu rikitarwa, an yi amfani da ƙungiyoyi huɗu da biyar da aka inganta da kuma centroids masu alaƙa da su (bayanan siffa) don samfuran da aka yi amfani da su da zafi da kuma waɗanda aka yi musu sanyi, bi da bi. Saboda haka, ana iya samun kashi (%) na Fe2+ da Fe3+ ta hanyar haɗa LCF da aka nuna a Hoto na 4. An yi amfani da Epseudo mai yuwuwar pseudoelectrode a matsayin aikin Fe0 don bayyana rashin daidaituwar microchemical na fim ɗin oxide na saman. Ana kimanta Epseudo kusan ta hanyar ƙa'idar haɗawa,
inda \(\rm{E}_{\rm{Fe}/\rm{Fe}^{2 + (3 + )}}\) yayi daidai da \(\rm{Fe} + 2e^ – \ to \rm {Fe}^{2 + (3 + )}\), 0.440 da 0.036 V, bi da bi. Yankunan da ke da ƙarancin ƙarfin suna da babban abun ciki na mahaɗin Fe3+. Rarraba mai yuwuwa a cikin samfuran da aka lalata ta yanayin zafi yana da hali mai layi tare da matsakaicin canji na kusan 0.119 V (Hoto na 6a, b). Wannan rarraba mai yuwuwa yana da alaƙa da yanayin saman (Hoto na 6a). Ba a lura da wasu canje-canje masu dogaro da matsayi a cikin ciki na laminar ba (Hoto na 6b). Akasin haka, don haɗin oxides daban-daban tare da abubuwan da ke ciki daban-daban na Fe2+ da Fe3+ a cikin SDSS mai sanyi, mutum zai iya lura da yanayin da ba shi da daidaito na pseudopotential (Hoto na 6c, d). Fe3+ oxides da/ko (oxy) hydroxides sune manyan abubuwan da ke haifar da tsatsa a cikin ƙarfe kuma suna iya shiga cikin iskar oxygen da ruwa50. A wannan yanayin, ana ɗaukar tsibiran da ke da wadataccen Fe3+ a matsayin waɗanda aka rarraba a cikin gida kuma ana iya ɗaukar su a matsayin yankunan da suka lalace. A lokaci guda, ana iya amfani da gradient a cikin filin yuwuwar, maimakon cikakken ƙimar yuwuwar, a matsayin alamar wurin wuraren tsatsa masu aiki. Wannan rarrabawar Fe2+ da Fe3+ mara daidaito a saman SDSS mai sanyi na iya canza sinadaran gida da kuma samar da yankin saman aiki mai amfani a cikin rugujewar fim ɗin oxide da halayen tsatsa, ta haka yana ba da damar ci gaba da tsatsa na matrix na ƙarfe, wanda ke haifar da tsatsa ta ciki. Bambancin kadarori da raguwar kadarori na kariya na layin wucewa.
K-na nufin ƙungiyoyi da kuma centroids na XAS masu dacewa a yankin gefen Fe L2.3 na X-PEEM ac mai zafi da kuma df na SDSS mai sanyi. a, d K-na nufin taswirar cluster da aka lulluɓe akan hotunan X-PEEM. An ambaci ƙarfin pseudoelectrode da aka ƙididdige (Epseudo) tare da taswirar cluster na K-na nufin. Hasken hoton X-PEEM, kamar launi a Hoto na 2 yana daidai da ƙarfin sha X-ray.
Yanayin sinadarai daban-daban na Fe wanda ya yi daidai da Cr amma yana haifar da lalacewar fim ɗin oxide daban-daban da kuma tsatsa a cikin Ce-2507 mai zafi da sanyi. An yi nazari sosai kan wannan siffa ta Ce-2507 mai sanyi. Dangane da samuwar oxides da hydroxides na Fe a cikin iskar yanayi a cikin wannan aikin kusan tsaka tsaki, halayen sune kamar haka:
Abubuwan da ke sama suna faruwa ne a cikin waɗannan yanayi bisa ga nazarin X-PEEM. Ƙaramin kafada da ya dace da Fe0 yana da alaƙa da ƙarfen ƙarfe da ke ƙarƙashinsa. Haɗakar ƙarfe Fe tare da muhalli yana haifar da samuwar Layer na Fe(OH)2 (daidaitawa (5)), wanda ke haɓaka siginar Fe2+ a cikin XAS na gefen Fe L. Tsawon lokaci da aka fallasa ga iska na iya haifar da samuwar Fe3O4 da/ko Fe2O3 oxides bayan Fe(OH)252,53. Siffofi biyu masu karko na Fe, Fe3O4 da Fe2O3, suma suna iya samuwa a cikin Layer mai karewa mai wadata na Cr3+, wanda Fe3O4 ya fi son tsari iri ɗaya da manne. Kasancewar duka biyun yana haifar da yanayin iskar shaka (bakan XAS-1). Bakan XAS-2 galibi yayi daidai da Fe3O4. Yayin da lura da bakan XAS-3 a wurare da yawa ya nuna cikakken juyawa zuwa γ-Fe2O3. Tunda zurfin shigar hasken X-ray ɗin da aka buɗe ya kai kusan nm 50, siginar da ke fitowa daga ƙananan layukan yana haifar da ƙarin ƙarfi na kololuwar A.
Bakan XPA ya nuna cewa bangaren Fe a cikin fim ɗin oxide yana da tsari mai layi tare da layin Cr oxide. Sabanin alamun rashin daidaituwa saboda rashin daidaituwa na gida na Cr2O3 yayin tsatsa, duk da daidaitaccen Layer na Cr2O3 a cikin wannan aikin, an lura da ƙarancin juriyar tsatsa a wannan yanayin, musamman ga samfuran da aka naɗe da sanyi. Ana iya fahimtar halayen da aka lura a matsayin bambancin yanayin iskar shaka a cikin saman Layer (Fe), wanda ke shafar aikin tsatsa. Saboda irin wannan stoichiometry na saman Layer (iron oxide) da ƙananan Layer (chromium oxide)52,53 ingantacciyar hulɗa (mannewa) tsakanin su yana haifar da jinkirin jigilar ƙarfe ko ions na oxygen a cikin raga, wanda, bi da bi, yana haifar da ƙaruwar juriyar tsatsa. Saboda haka, rabon stoichiometric mai ci gaba, watau yanayin iskar shaka ɗaya na Fe, ya fi dacewa da canje-canjen stoichiometric kwatsam. SDSS mai nakasasshen zafi yana da saman da ya fi daidaito, Layer mai kauri mai kauri, da kuma ingantaccen juriyar tsatsa. Duk da cewa ga SDSS mai sanyi, kasancewar tsibiran Fe3+ masu arzikin ƙasa a ƙarƙashin layin kariya yana keta mutuncin saman kuma yana haifar da tsatsa ta galvanic tare da substrate da ke kusa, wanda ke haifar da raguwar kaifi a cikin Rp (Tebur 1). An rage yawan bakan EIS da juriyar tsatsa. Ana iya ganin cewa rarraba tsibiran Fe3+ masu arzikin ƙasa saboda lalacewar filastik galibi yana shafar juriyar tsatsa, wanda shine babban ci gaba a cikin wannan aikin. Don haka, wannan binciken yana gabatar da hotunan microscopic na raguwar juriyar tsatsa na samfuran SDSS da aka yi nazari a kansu ta hanyar lalata filastik.
Bugu da ƙari, duk da cewa haɗakar abubuwa masu ƙarancin ƙasa a cikin ƙarfe mai matakai biyu yana nuna kyakkyawan aiki, hulɗar wannan sinadarin ƙari tare da matrix na ƙarfe na mutum ɗaya dangane da ɗabi'ar tsatsa bisa ga bayanan na'urar hangen nesa ta spectroscopic har yanzu ba ta da tabbas. Bayyanar siginar Ce (ta hanyar XAS M-gefe) tana bayyana ne kawai a wurare kaɗan yayin birgima mai sanyi, amma tana ɓacewa yayin lalacewar zafi na SDSS, yana nuna hazo na Ce na gida a cikin matrix na ƙarfe, maimakon haɗakar abubuwa iri ɗaya. Duk da cewa ba ya inganta halayen injiniya na SDSS6,7 sosai, kasancewar abubuwan ƙasa masu ƙarancin ƙasa yana rage girman abubuwan da aka haɗa kuma ana tsammanin yana hana rami a yankin farko54.
A ƙarshe, wannan aikin ya bayyana tasirin bambancin saman akan tsatsa na 2507 SDSS wanda aka gyara da cerium ta hanyar ƙididdige sinadaran da ke cikin sassan nanoscale. Mun amsa tambayar dalilin da yasa bakin ƙarfe ke lalacewa ko da a ƙarƙashin wani Layer na oxide mai kariya ta hanyar ƙididdige ƙananan tsarinsa, sunadarai na saman, da sarrafa sigina ta amfani da clustering na K-means. An tabbatar da cewa tsibiran da ke da wadataccen Fe3+, gami da haɗin kai na octahedral da tetrahedral tare da dukkan fasalin gaurayen Fe2+/Fe3+, sune tushen lalacewa da tsatsa na fim ɗin oxide mai sanyi SDSS. Tsibiran Nanoislands waɗanda Fe3+ suka mamaye suna haifar da mummunan juriya na tsatsa ko da a gaban isasshen Layer na stoichiometric Cr2O3 passivating. Baya ga ci gaban hanyoyin tantance tasirin bambancin sinadarai na nanoscale akan tsatsa, ana sa ran ci gaba da aiki zai zaburar da hanyoyin injiniya don inganta juriya na tsatsa na bakin ƙarfe yayin yin ƙarfe.
Don shirya ingot na Ce-2507 SDSS da aka yi amfani da shi a cikin wannan binciken, an narkar da wani hade-hade wanda ya haɗa da Fe-Ce master alloy wanda aka rufe da bututun ƙarfe mai tsabta a cikin tanda mai matsakaicin mita 150 don samar da ƙarfe mai narkewa sannan aka zuba shi a cikin mold. An jera abubuwan da aka auna (wt%) a cikin Tebur na Ƙarin Bayani na 2. Da farko ana yin amfani da ingots da zafi zuwa tubalan. Sannan an rufe shi a 1050°C na tsawon mintuna 60 don samun ƙarfe a cikin yanayin maganin da ya yi ƙarfi, sannan a kashe shi a cikin ruwa zuwa zafin ɗaki. An yi nazarin samfuran da aka yi nazari dalla-dalla ta amfani da TEM da DOE don nazarin matakai, girman hatsi da yanayin halittarsu. Ana iya samun ƙarin bayani game da samfurori da tsarin samarwa a wasu tushe6,7.
An sarrafa samfuran silinda (φ10 mm×15 mm) don matsewa mai zafi ta yadda axis na silinda ya kasance daidai da alkiblar nakasassu na tubalin. An gudanar da matsewa mai zafi a yanayin zafi daban-daban a cikin kewayon 1000-1150°C ta amfani da na'urar kwaikwayo ta thermal Gleeble-3800 a cikin ƙimar matsewa akai-akai a cikin kewayon 0.01-10 s-1. Kafin nakasassu, an dumama samfuran a cikin ƙimar 10 °C s-1 na tsawon mintuna 2 a zafin da aka zaɓa don kawar da ƙimar zafin jiki. Bayan cimma daidaiton zafin jiki, an canza samfurin zuwa ƙimar matsewa ta gaske ta 0.7. Bayan nakasassu, an kashe samfuran nan da nan da ruwa don kiyaye tsarin nakasassu. Sannan an yanke samfurin da aka taurare a layi ɗaya da alkiblar matsewa. Don wannan binciken na musamman, mun zaɓi samfurin da yanayin matsewa mai zafi na 1050°C, 10 s-1 saboda microhardness da aka lura ya fi sauran samfuran7.
An yi amfani da manyan samfuran (80 × 10 × 17 mm3) na maganin Ce-2507 mai ƙarfi a cikin injin niƙa mai matakai uku na LG-300 mai naɗi biyu mai tsari uku tare da mafi kyawun halayen injiniya tsakanin duk sauran matakan nakasa6. Matsakaicin ƙarfin matsi da raguwar kauri ga kowane hanya shine 0.2 m·s-1 da 5%, bi da bi.
An yi amfani da wurin aiki na lantarki na Autolab PGSTAT128N don auna lantarki na SDSS bayan an yi birgima da sanyi zuwa raguwar kauri da kashi 90% (daidai da nau'in gaske mai daidai da 1.0) kuma bayan an matse shi da zafi a 1050°C na 10 s-1 zuwa nau'in gaske na 0.7. Wurin aiki yana da ƙwayar lantarki mai uku tare da electrode calomel mai cikakken ƙarfi azaman electrode na tunani, electrode na counter graphite, da samfurin SDSS azaman electrode mai aiki. An yanke samfuran zuwa silinda masu diamita na 11.3 mm, zuwa gefunan da aka haɗa wayoyin jan ƙarfe. Sannan an gyara samfuran da epoxy, suna barin yanki mai aiki na 1 cm2 a matsayin electrode mai aiki (ƙasa na samfurin silinda). Yi hankali yayin wargaza epoxy da kuma gogewa da gogewa daga baya don guje wa fashewa. An niƙa saman aikin kuma an goge shi da dakatarwar goge lu'u-lu'u mai girman barbashi na 1 μm, an wanke shi da ruwa mai narkewa da ethanol, sannan aka busar da shi a cikin iska mai sanyi. Kafin a auna sinadaran lantarki, an fallasa samfuran da aka goge a iska na tsawon kwanaki da dama don samar da fim ɗin oxide na halitta. Ana amfani da maganin ruwa na FeCl3 (6.0 wt%), wanda aka daidaita zuwa pH = 1.0 ± 0.01 tare da HCl bisa ga shawarwarin ASTM, don hanzarta tsatsagewar bakin karfe 55 saboda yana lalata idan akwai ions na chloride masu ƙarfin oxidizing da ƙarancin pH. Ka'idojin muhalli G48 da A923. A nutsar da samfurin a cikin maganin gwaji na tsawon awa 1 don isa ga yanayin da ya dace kafin a yi kowane ma'auni. Don samfuran da aka yi da ƙarfi, waɗanda aka yi da zafi, da waɗanda aka yi da sanyi, an gudanar da ma'aunin impedance a cikin ƙarfin da'ira (OPC) na 0.39, 0.33, da 0.25 V, bi da bi, a cikin kewayon mita daga 1 105 zuwa 0.1 Hz tare da girman 5 mV. An maimaita duk gwaje-gwajen sinadarai aƙalla sau 3 a ƙarƙashin yanayi ɗaya don tabbatar da sake haifar da bayanai.
Don ma'aunin HE-SXRD, an auna tubalan ƙarfe masu siffar murabba'i mai girman 1 × 1 × 1.5 mm3 don auna yanayin yanayin haske na injin juyawa mai ƙarfi na Brockhouse a CLS, Kanada56. An gudanar da tattara bayanai a cikin tsarin Debye-Scherrer ko tsarin watsawa a zafin ɗaki. Tsawon hasken X-ray da aka daidaita tare da mai auna LaB6 shine 0.212561 Å, wanda yayi daidai da 58 keV, wanda ya fi na Cu Kα (8 keV) wanda aka saba amfani da shi azaman tushen hasken X-ray na dakin gwaje-gwaje. An samo samfurin a nesa na 740 mm daga na'urar ganowa. Girman gano kowane samfurin shine 0.2 × 0.3 × 1.5 mm3, wanda aka ƙayyade ta girman hasken da kauri samfurin. An tattara duk bayanan ta amfani da na'urar gano yankin Perkin Elmer, na'urar gano X-ray mai faɗi, pixels 200 µm, 40 × 40 cm2 ta amfani da lokacin fallasa na 0.3 s da firam 120.
An gudanar da ma'aunin X-PEEM na tsarin samfuri guda biyu da aka zaɓa a tashar ƙarshe ta Beamline MAXPEEM PEEM a dakin gwaje-gwaje na MAX IV (Lund, Sweden). An shirya samfura kamar yadda ake yi da ma'aunin lantarki. An ajiye samfuran da aka shirya a cikin iska na tsawon kwanaki da yawa kuma an cire gas ɗin a cikin ɗakin injin mai ƙarfi kafin a haskaka su da photons na synchrotron. An sami ƙudurin makamashi na layin katako ta hanyar auna bakan samar da ion a yankin motsawa daga N 1 s zuwa 1\(\pi _g^ \ast\) kusa da hv = 401 eV a cikin N2 tare da dogaro da makamashin photon akan E3/2, 57. Kimanin bakan ya ba ΔE (faɗin layin bakan) kusan 0.3 eV a cikin kewayon makamashin da aka auna. Saboda haka, an kiyasta ƙudurin ƙarfin hasken rana shine E/∆E = 700 eV/0.3 eV > 2000 da kuma flux ≈1012 ph/s ta hanyar amfani da wani sinadari mai suna SX-700 wanda aka gyara tare da sinadari mai layi 1200 mm−1 na Si don gefen Fe 2p L2,3, Cr 2p L2,3, Ni 2p L2,3, da gefen Ce M4,5. Saboda haka, an kiyasta ƙudurin kuzarin beamline shine E/∆E = 700 eV/0.3 eV > 2000 da kuma flux ≈1012 ph/s ta hanyar amfani da wani ingantaccen SX-700 monochromator tare da Si 1200-line mm−1 grating don Fe 2p L2.3 edge, Cr 2p L2.3 edge, Ni 2p L2.3 edge, da Ce M4.5 edge. Таkym obrazom, эnergеtycheskoe razrешение knala chuchka bыlo otseneno kak E/∆E = 700 эВ/0,3 эВ> 2000 и 2000 и 2000 при использовании модифицированного монохроматора SX-700 с решеткой Si 1200 штрихов/мм для Fe кромать, L2,3, кромка Ni 2p L2,3 da кромка Ce M4,5. Saboda haka, an kiyasta ƙudurin kuzari na tashar hasken wutar lantarki kamar E/∆E = 700 eV/0.3 eV > 2000 da kuma kwararar iska ≈1012 f/s ta amfani da wani sinadari mai suna SX-700 da aka gyara tare da sinadari mai layi 1200/mm don gefen Fe 2p L2,3, gefen Cr 2p L2.3, gefen Ni 2p L2.3, da gefen Ce M4.5.因此，光束线能量分辨率估计为E/ΔE = 700 eV/0.3 eV > 2000光栅的改进的SX-700 单色器用于Fe 2p L2,3 边缘,因此 ， 光束线 光束线1200 线 mm-1 光栅 改进 的 SX-700 单色器 于 于 于 用 用 Fe 2p L2.3 边缘、Cr 2p L2.3边缘和Ce M4.5 边缘.Saboda haka, lokacin amfani da wani sinadari mai siffar SX-700 da aka gyara tare da layin Si na 1200. 3, Cr gefen 2p L2.3, Ni gefen 2p L2.3 da Ce gefen M4.5.An yi amfani da na'urar auna ƙarfin photon a matakai 0.2 eV. A kowane makamashi, an yi rikodin hotunan PEEM ta amfani da na'urar gano TVIPS F-216 CMOS mai fiber coupled tare da kwandon shara 2 x 2, wanda ke ba da ƙudurin pixels 1024 x 1024 a cikin filin gani na 20 µm. Lokacin fallasa hotunan shine 0.2 s, matsakaicin firam 16. An zaɓi kuzarin hoton photoelectron ta yadda zai samar da matsakaicin siginar lantarki ta biyu. An gudanar da duk ma'auni a lokacin da aka saba amfani da hasken photon mai layi-layi. Ana iya samun ƙarin bayani game da ma'auni a cikin wani bincike da ya gabata. Bayan nazarin yanayin gano yawan amfanin lantarki (TEY) da aikace-aikacensa a cikin X-PEEM49, an kiyasta zurfin gwajin wannan hanyar ya kai kusan 4-5 nm don siginar Cr da kuma kusan 6 nm don Fe. Zurfin Cr yana kusa da kauri na fim ɗin oxide (~4 nm) 60,61 yayin da zurfin Fe ya fi kauri girma. XRD da aka tara a gefen Fe L cakuda ne na XRD na ƙarfe oxides da Fe0 daga matrix. A cikin yanayin farko, ƙarfin electrons da aka fitar ya fito ne daga dukkan nau'ikan electrons da ke ba da gudummawa ga TEY. Duk da haka, siginar ƙarfe mai tsabta tana buƙatar ƙarin kuzarin motsi don electrons su ratsa ta cikin layin oxide zuwa saman kuma mai nazarin ya tattara su. A wannan yanayin, siginar Fe0 galibi tana faruwa ne saboda LVV Auger electrons, da kuma electrons na biyu da suka fitar. Bugu da ƙari, ƙarfin TEY da waɗannan electrons ke bayarwa yana lalacewa yayin hanyar tserewa ta electron, wanda hakan ke ƙara rage martanin Fe0 a cikin taswirar ƙarfe XAS.
Haɗa haƙar bayanai a cikin kubin bayanai (bayanan X-PEEM) muhimmin mataki ne wajen fitar da bayanai masu dacewa (halayen sinadarai ko na zahiri) ta hanyar amfani da hanyoyi daban-daban. Ana amfani da haɗa K-ma'ana a fannoni da dama, ciki har da hangen nesa na na'ura, sarrafa hoto, gane tsari ba tare da kulawa ba, basirar wucin gadi, da kuma nazarin rarrabuwa. Misali, haɗa K-ma'ana ya yi aiki sosai wajen haɗa bayanan hoto masu hangen nesa. A ƙa'ida, ga bayanai masu fasali da yawa, tsarin K-ma'ana zai iya haɗa su cikin sauƙi bisa ga bayanai game da halayensu (halayen makamashin photon). Tsarin K-ma'ana tsari ne na maimaitawa don raba bayanai zuwa ƙungiyoyin K marasa haɗuwa (ƙungiya), inda kowane pixel ya kasance cikin wani rukuni dangane da rarrabawar sarari na rashin daidaituwar sinadarai a cikin tsarin ƙarfe na microstructural. Tsarin K-ma'ana ya haɗa da matakai biyu: a mataki na farko, ana ƙididdige centroids na K, kuma a mataki na biyu, kowane batu an sanya shi gungu tare da centroids maƙwabta. An bayyana tsakiyar nauyi na rukuni a matsayin ma'aunin lissafi na ma'aunin bayanai (bakan XAS) na wannan rukuni. Akwai nisan da za a ayyana centroids maƙwabta a matsayin nisan Euclidean. Don hoton shigarwa na px,y (inda x da y sune ƙuduri a cikin pixels), CK shine tsakiyar nauyi na rukuni; sannan za a iya raba wannan hoton (rukunin) zuwa ƙungiyoyin K ta amfani da K-means63. Matakan ƙarshe na tsarin tattarawa na K-means sune:
Mataki na 2. Lissafa membobin dukkan pixels bisa ga centroid na yanzu. Misali, ana ƙididdige shi daga nisan Euclidean d tsakanin tsakiya da kowane pixel:
Mataki na 3 Sanya kowane pixel zuwa ga centroid mafi kusa. Sannan sake lissafin matsayin centroid na K kamar haka:
Mataki na 4. Maimaita tsarin (daidaitawa (7) da (8)) har sai centroids sun haɗu. Sakamakon ingancin tarin ƙarshe yana da alaƙa sosai da mafi kyawun zaɓin centroids na farko. Don tsarin bayanan PEEM na hotunan ƙarfe, yawanci X (x × y × λ) kubi ne na bayanan jeri na 3D, yayin da axes x da y suna wakiltar bayanan sarari (ƙudurin pixel) kuma axis λ ya yi daidai da hoton hasken wutar lantarki na photon. Ana amfani da algorithm na nufin K don bincika yankunan da ke da sha'awa a cikin bayanan X-PEEM ta hanyar raba pixels (gungu ko ƙananan tubalan) bisa ga siffofin haskensu da kuma cire mafi kyawun centroids (bayanan hasken XAS) don kowane rukuni na nazari). Ana amfani da shi don nazarin rarraba sararin samaniya, canje-canjen hasken gida, halayen iskar shaka, da yanayin sinadarai. Misali, an yi amfani da algorithm na tarin K don yankunan Fe L-gefen da Cr L-gefen a cikin X-PEEM mai zafi da sanyi. An gwada adadi daban-daban na rukunin K (yankunan ƙananan tsari) don nemo mafi kyawun rukuni da centroids. Lokacin da aka nuna waɗannan lambobi, ana sake sanya pixels zuwa centroids ɗin rukuni masu dacewa. Kowace rarraba launi tana daidai da tsakiyar cluster, tana nuna tsarin sarari na abubuwa masu sinadarai ko na zahiri. centroids ɗin da aka cire haɗuwa ne na layi na tsararren spectra.
Ana samun bayanai masu goyon bayan sakamakon wannan binciken bisa ga buƙata mai ma'ana daga marubucin WC.
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