Qhov sib txawv tseem ceeb ntawm stoichiometric thiab nonstoichiometric defects yog qhov tsis xws luag stoichiometric tsis cuam tshuam lub stoichiometry ntawm cov compound whereas nonstoichiometric defects cuam tshuam lub stoichiometry ntawm cov compound.
Muaj ob hom kev tsis xws luag tam sim no hauv cov qauv siv lead ua; xws li, stoichiometric defects thiab nonstoichiometric defects. Nyob rau hauv ib tug stoichiometric compound, nws cov tshuaj formula qhia qhov piv ntawm cov cations thiab anions nyob rau hauv lub compound.
Stoichiometric Defects yog dab tsi?
Stoichiometric defects yog cov uas tsis cuam tshuam rau stoichiometry ntawm ib qho chaw. Qhov ntawd txhais tau hais tias qhov tsis xws luag stoichiometric tsis hloov qhov piv ntawm cations thiab anions tam sim no hauv cov qauv siv lead ua. Muaj ntau ntau yam ntawm stoichiometric defects;
Interstitial Defects
Hauv cov qauv siv lead ua, feem ntau, muaj qhov chaw tsis muaj chaw nyob. Cov atoms me me tuaj yeem tuav cov chaw no hauv qhov kev teeb tsa uas muaj zog txaus nyiam (feem ntau, qhov chaw ntawm qhov chaw sib txuas ua rau muaj zog tag nrho ntawm cov siv lead ua). Yog li ntawd, muaj ions nyob rau hauv qhov chaw interstitial ua rau interstitial defects.
Schottky Defects
Schottky qhov teeb meem tsim thaum cov cations thiab anions tshem tawm ntawm cov qauv siv lead ua nyob rau hauv cov lej sib npaug. Txawm li cas los xij, qhov hluav taws xob nruab nrab ntawm cov siv lead ua tseem tsis hloov vim tias cov lej ntawm cov nqi raug tshem tawm ntawm cov siv lead ua sib npaug. Hom kev tsis haum no tshwm sim hauv cov muaju uas muaj cations thiab anions ntawm qhov ntau thiab tsawg.
Daim duab 01: Schottky thiab Frenkel Defects
Frenkel Defects
A Frenkel qhov tsis xws luag tshwm sim thaum ib qho ion ntawm cov siv lead ua lattice tshem tawm thiab nyob hauv ib qho chaw interstitial ntawm cov qauv siv lead ua. Txawm li cas los xij, tus nqi hluav taws xob ntawm cov siv lead ua tseem tsis hloov pauv vim tsis muaj ions raug tshem tawm lossis ntxiv los ntawm sab nraud.
Nonstoichiometric Defects yog dab tsi?
Nonstoichiometric defects yog qhov tsis xws hauv cov qauv siv lead ua uas cuam tshuam rau stoichiometry ntawm cov siv lead ua. Nyob rau hauv lwm yam lus, nonstoichiometric defects hloov lub stoichiometry ntawm lub crystal system. Thaum nonstoichiometric tsis xws luag nyob rau hauv ib tug siv lead ua qauv, qhov piv ntawm cov constituent ions ntawm lub compound ua nonstoichiometric. Muaj ob yam tseem ceeb ntawm nonstoichiometric defects;
Metal Excess Defect
Muaj ob hom hlau ntau dhau lawm. Ua ntej ib qho yog cov hlau tsis xws luag vim anionic vacancy. Hauv qhov no, qhov tsis xws luag tshwm sim vim tsis muaj anion los ntawm lub lattice. Txawm li cas los xij, cov electrons ntawm lub lattice tseem tsis hloov. Qhov thib ob yog cov hlau ntau dhau qhov tsis xws luag vim muaj cov cations ntxiv nyob rau hauv qhov chaw interstitial. Ntawm no, qhov tsis xws luag yog pom tau thaum cov ions zoo nyob hauv qhov chaw nruab nrab ntawm cov lattice.
Metal Deficiency Defect
Cov kev tsis zoo no kuj muaj ob hom; qhov tsis xws luag vim cation vacancies thiab ntxiv anions occupying qhov chaw interstitial ntawm lub lattice. Thaum tus nqi zoo ploj lawm los ntawm lub lattice, cov cations nyob ze sib npaug rau qhov tsis zoo ntxiv. Hom kab mob no hu ua cation vacancy defects. Lub caij no, thaum ib qho anion ntxiv nyob hauv qhov chaw nruab nrab ntawm lub lattice, cov cations nyob ze sib npaug rau qhov tsis zoo ntxiv. Hom defect no yog hom thib ob ntawm cov hlau tsis xws luag.
Qhov txawv ntawm Stoichiometric thiab Nonstoichiometric Defects yog dab tsi?
Stoichiometric vs Nonstoichiometric Defects |
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| Stoichiometric defects yog cov uas tsis cuam tshuam rau stoichiometry ntawm ib qho compound. | Nonstoichiometric defects yog qhov tsis xws ntawm cov qauv siv lead ua uas cuam tshuam rau stoichiometry ntawm cov siv lead ua. |
| Effect on Stoichiometry | |
| Lawv tsis cuam tshuam rau stoichiometry ntawm cov compound. | Lawv hloov cov stoichiometry ntawm cov compound. |
| Muaj ntau hom; xws li, interstitial defects, scottky defects, thiab Frenkel defects. | Hlau ntau dhau thiab cov hlau tsis muaj peev xwm yog ob hom tseem ceeb tawm ntawm ob peb |
Summary – Stoichiometric vs Nonstoichiometric Defects
Cov tsis xws luag yog cov ntsiab lus txawv txawv hauv cov qauv siv lead ua. Muaj ob hom kev tsis xws luag hu ua stoichiometric defects thiab nonstoichiometric defects. Qhov txawv ntawm stoichiometric thiab nonstoichiometric defects yog tias qhov tsis xws luag stoichiometric tsis cuam tshuam lub stoichiometry ntawm cov compound whereas nonstoichiometric defects cuam tshuam lub stoichiometry ntawm lub compound.
