Qhov sib txawv tseem ceeb ntawm cov hlau tsis zoo thiab cov hlau tsis muaj peev xwm yog cov hlau tsis xws luag yog tshwm sim los ntawm anionic vacancies thiab ntxiv cations nyob rau hauv qhov chaw interstitial whereas hlau deficiency yog tshwm sim los ntawm cationic vacancies thiab ntxiv anions nyob rau hauv lub interstitial qhov chaw.
Hlau qhov tsis xws luag thiab hlau tsis muaj peev xwm yog ob hom kev tsis xws peb tuaj yeem soj ntsuam hauv cov khoom siv lead ua lattices ntawm qee yam khoom. Cov teeb meem no tshwm sim vim muaj los yog tsis muaj cations los yog anions nyob rau hauv lub crystal lattices.
Hlau Excess Defect yog dab tsi?
Ib qho hlau tsis xws luag yog hom siv lead ua tsis xws luag uas tshwm sim hauv cov iav siv lead ua. Ib qho anionic vacancy lossis ib qho cation ntxiv ua rau qhov tsis xws luag. Vim tias muaj cov teeb meem no nyob rau hauv cov khoom uas tsis yog-stoichiometric inorganic, cov khib nyiab no muaj cov ntsiab lus tseem ceeb hauv cov khoom tsis-stoichiometric.
Thaum peb ua kom sov alkali hlau halides uas muab tso rau hauv ib qho chaw uas muaj cov vapor ntawm cov hlau alkali, nws ua rau tsim cov anion vacancies. Tom qab ntawd cov anions zoo li diffuse mus rau saum npoo ntawm cov siv lead ua thiab ua ke nrog cov hlau cations uas tau tsim tshiab. Ntawm no, ib qho hluav taws xob poob los ntawm cov hlau atom, ua raws li qhov sib txawv ntawm cov atom los ntawm cov khoom siv lead ua los tuav lub anionic qhov chaw tsis muaj, ua ib qho F-center hauv cov siv lead ua. F-centers uas tsim nyob rau hauv siv lead ua tuaj yeem muab cov xim sib txawv rau cov khoom siv lead ua lattice. E.g. sodium chloride - xim daj.
Muaj ob hom hlau ntau dhau:
Hlau ntau dhau vim Anionic Vacancy
Peb tuaj yeem pom cov hlau no ntau dhau ntawm alkali halides xws li sodium chloride thiab potassium chloride. Cov kev tsis zoo no suav nrog kev poob ntawm cov ions tsis zoo los ntawm qhov chaw lattice, uas tawm hauv qab lub qhov uas nyob hauv lub tshuab hluav taws xob txhawm rau txhawm rau tswj cov hluav taws xob sib npaug ntawm cov siv lead ua lattice. Cov electrons no ces zoo li cuab rau hauv qhov chaw tsis muaj anionic ntawm cov siv lead ua.
Hlau ntau dhau vim muaj Cations ntxiv
Hom hlau no dhau los ua cov ntaub ntawv thaum cua sov siv lead ua tebchaw, uas lawv tso cov cations ntxiv. Cov cations no nyiam nyob hauv qhov chaw interstitial ntawm cov siv lead ua lattice. Nrog rau qhov kev tsim cation no, cov hluav taws xob tso tawm (los ntawm cations) mus rau qhov chaw nyob sib ze. Ib qho piv txwv ntawm cov khoom uas tuaj yeem ua rau muaj qhov tsis xws luag yog ZnO, zinc oxide.
Hlau Deficiency Defect yog dab tsi?
Hlau deficiency yog ib hom siv lead ua defect uas tshwm sim nyob rau hauv siv lead ua lattices uas yog ib tug cation vacancy los yog ib qho anion ntxiv ua rau qhov tsis xws luag. Hom hlau tsis xws luag no tuaj yeem pom nyob rau hauv cov hlau complexes muaj qhov sib txawv. Muaj ob hom:
Metal Deficiency Defect vim Cation Vacancy
Nyob hauv hom kev tsis xws luag no, ib qho cation ploj lawm ntawm nws qhov chaw lattice; yog li ntawd, tus nqi tsis zoo ntxiv yog sib npaug los ntawm kev tau txais ob qhov txiaj ntsig zoo es tsis yog ib qho nqi. Cov teeb meem no tshwm sim feem ntau hauv cov tebchaw uas muaj oxidation sib txawv. E.g. npib tsib xee oxide.
Metal Deficiency Defect vim muaj cov Cations ntxiv
Nyob rau hauv cov siv lead ua lattices, cov anions ntxiv tshwm sim ntawm qhov chaw interstitial, thiab cov ions uas nyob ib sab ntawm lwm qhov chaw interstitial pab tswj cov hluav taws xob nruab nrab ntawm cov lattice. Hom no tsawg heev.
Dab tsi yog qhov txawv ntawm Cov Hlau Ntau Lawm thiab Hlau Deficiency Defect?
Hlau qhov tsis xws luag thiab hlau tsis muaj peev xwm yog ob hom kev tsis xws peb tuaj yeem soj ntsuam hauv cov khoom siv lead ua lattices ntawm qee yam khoom. Qhov sib txawv tseem ceeb ntawm cov hlau tsis zoo thiab cov hlau tsis muaj peev xwm yog cov hlau tsis xws luag yog tshwm sim los ntawm anionic qhov chaw tsis txaus thiab los ntawm cov cations ntxiv hauv qhov chaw interstitial whereas hlau deficiency yog tshwm sim los ntawm cationic vacancies thiab los ntawm anions ntxiv nyob rau hauv qhov chaw interstitial.
Hauv qab no yog cov ntsiab lus ntawm qhov sib txawv ntawm cov hlau ntau dhau thiab cov hlau tsis muaj peev xwm.
Summary – Hlau Excess Defect vs Hlau Deficiency Defect
Hlau tsis xws luag tshwm sim vim muaj los yog tsis muaj cations los yog anions nyob rau hauv lub siv lead ua lattices. Qhov sib txawv tseem ceeb ntawm cov hlau tsis zoo thiab cov hlau tsis muaj peev xwm yog cov hlau tsis xws luag yog tshwm sim los ntawm cov anionic vacancies thiab los ntawm cov cations ntxiv nyob rau hauv qhov chaw interstitial whereas hlau deficiency yog tshwm sim los ntawm cationic vacancies thiab los ntawm cov anions ntxiv nyob rau hauv lub interstitial qhov chaw..
