Qhov sib txawv tseem ceeb ntawm X ray diffraction thiab electron diffraction yog tias X ray diffraction cuam tshuam nrog qhov sib txawv ntawm qhov teeb meem ntawm X rays mus rau ntau qhov kev taw qhia whereas electron diffraction cuam tshuam ntawm ib qho hluav taws xob.
Ob qho X-ray diffraction thiab electron diffraction yog cov txheej txheem kev tshuaj xyuas uas peb tuaj yeem siv los kawm txog qhov teeb meem. Lwm cov txheej txheem zoo li no yog neutron diffraction. Cov txheej txheem no nthuav tawm cov qauv siv lead ua ntawm cov teeb meem. Yog li ntawd cov kev siv ntawm cov tswv yim no yog nyob rau hauv solid-state physics thiab chemistry.
X Ray Diffraction yog dab tsi?
X ray diffraction lossis X ray crystallography yog cov txheej txheem analytical uas peb siv los txiav txim cov qauv ntawm cov muaju. Yog li, txoj kev xav tom qab cov txheej txheem cuam tshuam nrog qhov sib txawv ntawm qhov xwm txheej X ray beam rau hauv ntau cov lus qhia. Nyob rau hauv luv luv, los ntawm kev ntsuas lub kaum sab xis thiab kev siv ntawm lub diffracted beams, peb muaj peev xwm txiav txim siab 3D daim duab ntawm lub electron ceev nyob rau hauv lub crystal. Yog li ntawd, cov electron ntom ntom muab cov haujlwm ntawm atoms hauv cov qauv siv lead ua. Tsis tas li ntawd, peb tuaj yeem txiav txim siab txog cov khoom siv tshuaj lom neeg thiab ntau yam ntaub ntawv ntxiv.
Daim duab 01: X-ray Diffractometer
Crystals tau teem caij tsis tu ncua atoms. X rays yog nthwv dej ntawm electromagnetic tawg. Yog li ntawd, cov atoms hauv cov siv lead ua tuaj yeem tawg cov X-ray beams los ntawm cov electrons ntawm cov atoms. Raws li qhov tshwm sim, X rays tawm tsam cov electrons tsim cov nthwv dej thib ob (sphereical nthwv dej) tawm ntawm cov hluav taws xob. Peb hu cov txheej txheem no ua "elastic scattering" thiab electron ua raws li tus scatterer. Txawm li cas los xij, cov nthwv dej no tso tseg ib leeg los ntawm kev cuam tshuam kev puas tsuaj.
Electron Diffraction yog dab tsi?
Electron diffraction yog ib qho kev tshuaj ntsuam xyuas uas peb siv los kawm txog qhov teeb meem. Yog li, txoj kev xav tom qab cov txheej txheem no suav nrog kev tua hluav taws xob ntawm tus qauv los saib xyuas cov qauv cuam tshuam ntawm cov kab hluav taws xob. Lub sij hawm cuam tshuam yog hais txog kev tsim cov nthwv dej los ntawm ob lub nthwv dej uas muaj ntau dua, qis dua lossis sib npaug amplitude. Feem ntau, peb ua qhov kev sim no hauv lub tshuab hluav taws xob xa hluav taws xob (TEM) lossis hauv tshuab ntsuas hluav taws xob (SEM). Cov cuab yeej no siv cov kab hluav taws xob nrawm nrawm (ua kom nrawm los ntawm qhov muaj peev xwm electrostatic).
Daim duab 02: Ib qho Electron Diffraction Pattern
Crystalline solids muaj cov qauv ntawm cov atoms. Cov qauv ntu ntu no ua raws li qhov sib txawv ntawm qhov sib txawv (splits thiab diffracs cov kab hluav taws xob rau hauv ob peb kab teeb uas taug kev sib txawv). Nyob ntawd, qhov tawg ntawm electrons tshwm sim nyob rau hauv kev kwv yees. Tus qauv ntawm diffraction muab peb cov ntsiab lus los kwv yees tus qauv ntawm cov siv lead ua. Txawm li cas los xij, cov txheej txheem no muaj kev txwv loj los ntawm theem teeb meem (qhov teeb meem ntawm kev poob ntawm cov ntaub ntawv hais txog theem uas tuaj yeem tshwm sim thaum ntsuas lub cev).
Qhov txawv ntawm X Ray Diffraction thiab Electron Diffraction yog dab tsi?
X ray diffraction thiab electron diffraction yog cov txheej txheem tseem ceeb uas peb tuaj yeem siv los txiav txim siab cov qauv siv lead ua ntawm crystalline solids. Qhov sib txawv tseem ceeb ntawm X ray diffraction thiab electron diffraction yog tias X ray diffraction cuam tshuam nrog qhov sib txawv ntawm qhov teeb meem ntawm X rays mus rau ntau qhov kev taw qhia thaum electron diffraction cuam tshuam ntawm ib qho hluav taws xob.
Ntxiv mus, X ray diffraction siv lub beam ntawm X rays thaum electron diffraction siv lub beam ntawm electrons. Raws li lwm qhov sib txawv tseem ceeb ntawm X ray thiab electron diffractions, electron diffraction yog txwv los ntawm theem teeb meem thaum nws tsis muaj txiaj ntsig zoo rau X ray diffraction. Cov ntsiab lus ntxiv tau pom nyob rau hauv infographic ntawm qhov sib txawv ntawm X ray diffraction thiab electron diffraction.
Summary – X Ray Diffraction vs Electron Diffraction
Ob qho X ray diffraction thiab electron diffraction yog cov txheej txheem uas peb tuaj yeem siv los txiav txim cov qauv ntawm cov muaju. Qhov sib txawv tseem ceeb ntawm X ray diffraction thiab electron diffraction yog tias X ray diffraction cuam tshuam nrog qhov sib txawv ntawm qhov teeb meem ntawm X rays mus rau ntau qhov kev taw qhia thaum electron diffraction cuam tshuam ntawm ib qho hluav taws xob.
