X-ray diffraction tsom xam yog ib txoj hauv kev los kawm txog cov qauv ntawm cov khoom. Nws yog ua raws li qhov sib txawv ntawm cov kab hluav taws xob X-ray ntawm qhov tshwj xeeb peb-dimensional siv lead ua gratings. Txoj kev tshawb no siv nthwv dej uas nws qhov ntev yog kwv yees li 1A, uas sib haum rau qhov loj ntawm lub atom. Nws yuav tsum tau hais tias X-ray diffraction tsom xam, ua ke nrog neutron thiab electron diffraction, yog hais txog diffraction txoj kev los txiav txim cov qauv ntawm cov khoom nyob rau hauv kev kawm.
Nws pab tshawb nrhiav cov qauv atomic, pawg chaw ntawm chav tsev ntawm tes, nws qhov loj thiab cov duab, nrog rau pawg symmetry ntawm cov muaju. Siv cov txheej txheem no, cov hlau thiab lawv ntau yam alloys, organic thiab inorganic compounds, minerals, amorphous cov ntaub ntawv, kua, thiab gases yog kawm. Qee zaum, X-ray diffraction tsom xam cov proteins, nucleic acids thiab lwm yam khoom siv.
Qhov kev tshuaj ntsuam no pab tsim cov qauv atomic ntawm cov ntaub ntawv crystalline, uas muaj cov qauv zoo thiab yog lub ntuj diffraction grating rau X-rays. Nws yuav tsum tau muab sau tseg tias nyob rau hauv kev kawm ntawm lwm yam tshuaj, X-ray diffraction tsom xam yuav tsum taumuaj cov muaju, uas yog ib qho tseem ceeb tab sis txoj hauj lwm nyuaj.
X-ray diffraction tau tshawb pom los ntawm Laue, lub hauv paus theoretical tau tsim los ntawm Woolf thiab Bragg. Debye thiab Scherrer tau pom zoo siv cov kev tshawb pom tsis tu ncua hauv lub luag haujlwm ntawm kev tshuaj xyuas. Nws yuav tsum tau hais tias tam sim no, X-ray diffraction tsom xam tseem yog ib txoj hauv kev zoo tshaj plaws rau kev txiav txim siab cov qauv ntawm cov khoom, vim nws yooj yim rau kev ua thiab tsis xav tau cov khoom siv tseem ceeb.
Nws tso cai rau koj los tshawb txog cov chav kawm sib txawv ntawm cov tshuaj, thiab tus nqi ntawm cov ntaub ntawv tau txais los txiav txim rau kev qhia txog cov txheej txheem tshiab. Yog li, thaum xub thawj lawv pib kawm cov qauv ntawm cov teeb meem uas siv cov kev ua ntawm interatomic vectors, tom qab ntawd cov txheej txheem ncaj qha rau kev txiav txim siab cov qauv siv lead ua tau tsim. Nws tsim nyog sau cia tias thawj cov tshuaj uas tau kawm siv X-rays yog sodium thiab potassium chlorides.
Kev kawm txog cov qauv spatial ntawm cov proteins pib hauv 30s ntawm lub xyoo pua xeem hauv UK. Cov ntaub ntawv tau txais tau nce mus rau molecular biology, uas ua rau nws muaj peev xwm nthuav tawm cov khoom tseem ceeb ntawm lub cev ntawm cov protein, nrog rau tsim thawj tus qauv ntawm DNA.
Txij li xyoo 1950, cov txheej txheem khoos phis tawj rau kev sib sau cov ntaub ntawv tau los ntawm X-ray cov qauv kev tshuaj xyuas pib tsim kom muaj zog.
Hnub no, synchrotrons tau siv. Lawv yog monochrome X-ray qhov chaw uas siv los irradiatesiv lead ua. Cov cuab yeej no tau zoo tshaj plaws thaum siv txoj kev ntawm multiwave anomalous dispersion. Nws yuav tsum raug sau tseg tias lawv tsuas yog siv hauv lub xeev cov chaw tshawb fawb. Cov chaw soj nstuam siv cov txheej txheem tsis muaj zog, uas ua haujlwm tsuas yog kuaj xyuas cov khoom siv lead ua zoo, nrog rau kom tau txais kev tshuaj xyuas ntxhib ntawm cov tshuaj.
