Lub peev xwm ntawm cov hlau nplaum ruaj khov los txhawb qhov chaw sib nqus sab nraud yog vim siv lead ua anisotropy hauv cov khoom sib nqus uas "locks" me me sib nqus hauv qhov chaw.Thaum qhov pib magnetization tau tsim, cov haujlwm no tseem zoo ib yam kom txog rau thaum lub zog tshaj qhov ntsuas qhov sib nqus tau siv, thiab lub zog yuav tsum tau cuam tshuam nrog cov hlau nplaum uas tsim los ntawm cov hlau nplaum ruaj khov sib txawv rau txhua yam khoom.Cov hlau nplaum tas mus li tuaj yeem tsim cov coercivity siab heev (Hcj), tswj kev sib haum xeeb hauv qhov muaj qhov sib nqus sab nraud.

Kev ruaj ntseg tuaj yeem piav qhia raws li cov khoom sib nqus rov ua dua ntawm cov khoom siv raws li cov xwm txheej hauv lub neej ntawm cov hlau nplaum.Cov yam ntxwv uas cuam tshuam rau cov hlau nplaum ruaj khov muaj xws li lub sijhawm, qhov kub thiab txias, kev hloov pauv ntawm qhov tsis txaus siab, qhov tsis zoo ntawm cov hlau nplaum, hluav taws xob, kev poob siab, kev ntxhov siab, thiab kev co.

Lub sij hawm tsis tshua muaj txiaj ntsig rau cov hlau nplaum niaj hnub niaj hnub, uas cov kev tshawb fawb tau pom tias muaj kev hloov pauv tam sim tom qab magnetization.Cov kev hloov no, hu ua "magnetic creep," tshwm sim thaum tsis tshua muaj zog sib nqus sib nqus tau cuam tshuam los ntawm thermal lossis magnetic zog hloov pauv, txawm tias nyob hauv ib puag ncig thermally ruaj khov.Qhov kev hloov pauv no txo ​​qis thaum cov cheeb tsam tsis ruaj khov txo qis.

Cov hlau nplaum tsis tshua muaj hauv ntiaj teb tsis zoo li yuav muaj qhov cuam tshuam no vim tias lawv cov coercivity siab heev.Ib txoj kev tshawb fawb sib piv ntawm lub sij hawm ntev dua piv rau cov hlau nplaum sib nqus qhia tau tias cov hlau nplaum tshiab uas tsis muaj zog hlau nplaum poob ib qho me me ntawm cov hlau nplaum sib nqus thaum lub sij hawm.Rau ntau tshaj 100,000 teev, qhov poob ntawm samarium cobalt cov ntaub ntawv yog qhov pib xoom, thaum qhov poob ntawm cov khoom tsis muaj permeability Alnico tsawg dua 3%.

Cov kev kub ntxhov poob rau hauv peb pawg: thim rov qab poob, rov qab tsis tau tab sis rov qab poob, thiab rov qab tsis tau thiab tsis rov qab poob.

Reversible Losses: Cov no yog qhov poob uas rov qab tau thaum cov hlau nplaum rov qab los rau nws qhov qub kub, qhov ruaj khov hlau nplaum ruaj khov tsis tuaj yeem tshem tawm qhov poob rov qab.Kev poob rov qab tau piav qhia los ntawm qhov rov qab qhov kub thiab txias coefficient (Tc), raws li qhia hauv cov lus hauv qab no.Tc tau qhia raws li feem pua ​​​​ntawm ib degree Celsius, cov lej no txawv ntawm cov qib tshwj xeeb ntawm txhua yam khoom siv, tab sis yog tus sawv cev ntawm cov khoom siv tag nrho.Qhov no yog vim qhov kub thiab txias coefficients ntawm Br thiab Hcj sib txawv heev, yog li qhov demagnetization nkhaus yuav muaj "inflection point" ntawm qhov kub siab.

Irreversible tab sis recoverable losses: Cov kev poob no yog txhais raws li ib feem ntawm demagnetization ntawm ib tug hlau nplaum vim raug rau qhov kub los yog tsawg, cov poob no tsuas yog rov qab los ntawm re-magnetization, cov hlau nplaum tsis tuaj yeem rov qab tau thaum qhov kub thiab txias rov qab los rau nws cov nqi qub.Cov kev poob no tshwm sim thaum qhov chaw khiav hauj lwm ntawm cov hlau nplaum yog qis dua qhov inflection point ntawm demagnetization nkhaus.Kev tsim cov hlau nplaum ruaj khov zoo yuav tsum muaj cov hlau nplaum sib nqus uas cov hlau nplaum ua haujlwm nrog cov permeability siab dua qhov cuam tshuam ntawm demagnetization nkhaus ntawm qhov kub siab, uas yuav tiv thaiv kev hloov pauv ntawm qhov kub thiab txias.

Irreversible Irrecoverable Loss: Cov hlau nplaum raug rau qhov kub siab heev dhau los ntawm kev hloov pauv hlau uas tsis tuaj yeem rov qab los ntawm remagnetization.Cov lus hauv qab no qhia qhov ntsuas kub tseem ceeb rau ntau yam khoom siv, qhov twg: Tcurie yog Curie qhov kub thiab txias uas lub sijhawm sib nqus qhov tseem ceeb yog randomized thiab cov khoom siv demagnetized;Tmax yog qhov siab tshaj plaws ua haujlwm kub ntawm cov khoom tseem ceeb hauv cov khoom siv dav dav.

Cov hlau nplaum yog ua kom kub ruaj khov los ntawm ib nrab demagnetizing cov hlau nplaum los ntawm kev nthuav tawm lawv mus rau qhov kub thiab txias hauv kev tswj hwm.Qhov qis me ntsis hauv flux ceev txhim kho qhov ruaj khov ntawm cov hlau nplaum, vim tias cov kev taw qhia tsawg dua yog thawj zaug poob lawv txoj kev taw qhia.Cov hlau nplaum ruaj khov zoo li no yuav nthuav tawm cov hlau nplaum tas li thaum raug sib npaug lossis qis dua.Tsis tas li ntawd, ib pawg ruaj khov ntawm cov hlau nplaum yuav pom qhov sib txawv ntawm cov flux qis dua thaum muab piv rau ib leeg, vim tias sab saum toj ntawm lub tswb nkhaus nrog cov yam ntxwv sib txawv yuav nyob ze rau batch tus nqi flux.