Cov Khoom Siv Sib Nqus ntawm Cov Khoom Siv Hlau
Kev sib nqus yog ib qho xwm txheej ntuj tsim uas tau ua rau tib neeg xav tsis thoob rau ntau pua xyoo. Txij li ntawm kev coj mus rau sab qaum teb tas li ntawm lub koob qhia mus rau lub peev xwm nqa cov khoom hnyav nrog cov hlau nplaum hluav taws xob, kev sib nqus ua lub luag haujlwm tseem ceeb hauv ntau yam ntawm tib neeg lub neej. Ib qho ntawm cov yam ntxwv zoo tshaj plaws ntawm kev sib nqus yog qhov uas qee cov hlau teb rau cov teb sib nqus. Tsab xov xwm no yuav tham txog cov khoom sib nqus ntawm cov khoom siv hlau, cov hom khoom sib nqus, cov yam ntxwv ntawm kev sib nqus hauv ntau yam hlau, thiab kev siv cov khoom sib nqus no.
Kev Taw Qhia Txog Magnetism
Kev sib nqus yog kev sib cuam tshuam ntawm lub zog sib nqus thiab cov khoom siv. Lub zog sib nqus yog lub zog vector uas piav qhia txog kev cuam tshuam ntawm lub zog sib nqus ntawm ib qho chaw tshwj xeeb hauv qhov chaw. Lub zog no tuaj yeem tsim los ntawm lub zog hluav taws xob (lub zog sib nqus hluav taws xob) lossis los ntawm cov khoom siv sib nqus tas mus li. Cov khoom siv teb rau lub zog sib nqus nyob ntawm nws qhov kev npaj atomic thiab cov qauv sab hauv.
Hom Khoom Siv Sib Nqus
Cov ntaub ntawv tuaj yeem sib txawv raws li lawv cov lus teb rau cov teb sib nqus ua ntau hom tseem ceeb: diamagnetic, paramagnetic, ferromagnetic, antiferromagnetic, thiab ferrimagnetic.
1. Diamagnetic:
Cov khoom siv diamagnetic tsis muaj lub zog sib nqus thaum tsis muaj lub zog sib nqus thiab yuav ua rau lub zog sib nqus tsis muaj zog heev uas tawm tsam qhov kev taw qhia ntawm lub zog sab nraud. Piv txwv li suav nrog bismuth thiab tooj liab. Feem ntau, cov khoom siv diamagnetic qhia txog kev txo qis ntawm lub zog sib nqus thiab tsis khaws cia magnetization thaum lub zog sab nraud raug tshem tawm.
2. Paramagnetic:
Cov khoom siv paramagnetic muaj cov atomic lossis molecular magnetic moments uas tsis sib txuas. Thaum raug rau lub zog magnetic, cov khoom siv no yuav raug magnetized rau hauv qhov kev taw qhia ntawm lub zog magnetic. Txawm li cas los xij, qhov magnetization tsis muaj zog thiab tsis nyob ntev tom qab lub zog sab nraud raug tshem tawm. Piv txwv ntawm cov khoom siv paramagnetic suav nrog txhuas, platinum, thiab manganese.
3. Ferromagnetic:
Ferromagnetic yog ib yam khoom ntawm cov hlau xws li hlau, cobalt, thiab nickel, uas cov atoms hauv lawv feem ntau sib phim lawv cov magnetic moments hauv tib qho kev taw qhia. Qhov no ua rau muaj magnetization muaj zog txawm tias tsis muaj lub teb magnetic sab nraud. Ferromagnets muaj ob yam ntxwv tseem ceeb: magnetic hysteresis thiab magnetic retentivity.
4. Tiv thaiv cov hlau nplaum:
Hauv cov khoom siv antiferromagnetic, lub zog sib nqus ntawm cov atoms lossis molecules uas nyob ib sab feem ntau tig lawv tus kheej mus rau ib leeg, ua rau muaj xoom lossis me me heev ntawm cov teb sib nqus. Thaum kub qis, antiferromagnetism feem ntau ruaj khov dua. Ib qho piv txwv ntawm cov khoom siv no yog magnetite (FeO).
5. Ferrimagnetic:
Cov khoom siv Ferrimagnetic xws li magnetite (Fe3O4) muaj cov zog sib nqus tsis sib npaug, ua rau muaj kev sib nqus raws li kev taw qhia. Ferrimagnetism yog lub hauv paus ntawm ntau cov khoom siv sib nqus ceramic siv hauv cov thev naus laus zis niaj hnub no.
Kev sib nqus hauv cov hlau
Txhua hom hlau muaj cov qauv atomic sib txawv, yog li nws cov lus teb rau cov teb magnetic sib txawv heev. Cov hlau uas kawm feem ntau hauv cov ntsiab lus ntawm magnetism yog hlau, cobalt, nickel, thiab qee cov alloys xws li permaloy (ib qho alloy nickel-iron).
1. Hlau (Fe):
Hlau yog ib qho piv txwv zoo ntawm cov hlau ferromagnetic. Cov hlau atoms muaj cov magnetic moments uas tau teeb tsa ua ib lub voj voog, uas tso cai rau hlau kom tswj tau nws cov magnetization thaum tsis muaj lub teb sab nraud. Nyob rau hauv qee qhov xwm txheej, xws li qhov kub ntawm xoom Kelvin, tag nrho cov hlau lub magnetic moments sib phim zoo kawg nkaus, tsim kom muaj lub teb magnetic muaj zog heev.
2. Cobalt (Co):
Ib yam li hlau, cobalt kuj yog hlau ferromagnetic. Txawm li cas los xij, cobalt muaj cov qauv siv lead ua sib txawv hu ua hexagonal close-packed. Cov qauv no muab cov khoom sib nqus sib txawv rau nws, suav nrog qhov kub Curie siab dua (kwv yees li 1388 K piv rau hlau 1043 K).
3. Nickel (Ni):
Nickel yog lwm yam hlau ferromagnetic. Nickel muaj lub ntsej muag-centered cubic (fcc) crystal structure, ua rau nws muaj zog magnetic zoo ib yam li hlau tab sis muaj qee qhov sib txawv tseem ceeb, xws li qhov saturation magnetization qis dua.
4. Cov Hlau Sib Nqus:
Cov hlau sib xyaw ntawm cov hlau no feem ntau muaj cov khoom sib nqus tshwj xeeb uas tsis pom muaj nyob rau hauv cov ntsiab lus ntshiab. Piv txwv li, permaloy muaj cov khoom sib nqus siab heev txawm tias feem ntau yog nickel. Qhov no yog vim muaj kev sib cuam tshuam nyuaj ntawm cov nickel thiab hlau atoms hauv cov qauv ntawm cov hlau sib xyaw.
Cov Ntawv Thov Sib Nqus Hauv Lub Neej Txhua Hnub
Qhov magnetism ntawm cov khoom siv hlau muaj ntau yam kev siv tseem ceeb hauv kev siv tshuab niaj hnub no thiab kev lag luam. Qee qhov ntawm cov kev siv no suav nrog:
1. Kev Khaws Cov Ntaub Ntawv:
Kev khaws cov ntaub ntawv sib nqus, xws li hauv cov hard disk drives (HDDs) thiab tape drives, yog ib qho kev siv tseem ceeb ntawm cov khoom ferromagnetic ntawm cov hlau. Cov ntaub ntawv ferromagnetic yog siv los sau cov ntaub ntawv hauv daim ntawv ntawm cov chaw sib nqus.
2. Cov Tshuab Hluav Taws Xob thiab Cov Tshuab Hluav Taws Xob:
Cov tshuab hluav taws xob thiab cov cav siv lub hauv paus ntsiab lus ntawm electromagnetic induction. Cov rotors thiab stators hauv cov tshuab hluav taws xob thiab cov cav feem ntau yog ua los ntawm hlau lossis lwm yam ferromagnetic alloys los ua kom muaj kev ua haujlwm ntawm kev hloov pauv hluav taws xob electromagnetic.
3. Lub tshuab hloov pauv:
Cov transformers siv los nce thiab nqis qhov voltage hauv cov kab ke faib hluav taws xob. Cov transformer cores feem ntau yog ua los ntawm silicon hlau, uas muaj cov khoom sib nqus zoo heev los ua kom muaj kev ua haujlwm zoo dua.
4. Cov Khoom Siv Hluav Taws Xob thiab Cov Sensors:
Ferrite yog ib yam khoom siv ferrimagnetic siv rau hauv ntau yam kev siv hluav taws xob, xws li lub xov tooj cua antenna cores, magnetic field sensors, thiab inductors.
Kev kaw
Kev nkag siab txog cov khoom siv hlau nplaum yog qhov tseem ceeb rau kev txhim kho thev naus laus zis niaj hnub no. Txij li cov qauv tseem ceeb ntawm lub cev mus rau kev siv ua haujlwm, qhov magnetism ntawm cov khoom siv hlau tseem yog ib qho kev tshawb fawb thiab kev tsim kho tshiab uas txaus nyiam thiab muaj txiaj ntsig. Los ntawm kev nkag siab txog cov yam ntxwv thiab cov lus teb ntawm ntau yam hlau rau cov teb magnetic, peb tuaj yeem ua kom zoo dua lawv siv hauv ntau yam khoom siv thev naus laus zis thiab cov txheej txheem, thaum kawg ua tau raws li tib neeg xav tau thiab txhim kho lub neej zoo.
