Cov hlau nplaum uas khaws lawv cov hlau nplaum tom qab qhov chaw sib nqus sab nraud raug tshem tawm yog hu ua cov hlau nplaum ruaj khov. Muaj qee cov hlau nplaum uas nquag siv: ferrite, neodymium hlau boron ruaj khov hlau nplaum, samarium cobalt. Dab tsi yog cov khoom tseem ceeb ntawm cov hlau nplaum ruaj khov?
Cov khoom tseem ceeb ntawm cov hlau nplaum ferrite: cov ntaub ntawv tseem ceeb yog BaFe12O19 thiab SrFe12O19. Ferrite hlau nplaum yog ua los ntawm ceramic technology. Qhov kev ntxhib los mos yog qhov nyuaj, tus nqi qis, thiab kev ua tau zoo yog nruab nrab. Nws tau dhau los ua cov hlau nplaum uas siv tau zoo tshaj plaws.
Cov khoom tseem ceeb ntawm NdFeB cov hlau nplaum ruaj khov: cov khoom siv hlau nplaum ruaj khov raws li intermetallic compound Re2fe14b. Cov khoom tseem ceeb yog cov ntsiab lus tsis tshua muaj hauv ntiaj teb, Fe, thiab N. Ntawm lawv, lub ntsiab tsis tshua muaj hauv ntiaj teb yog Nd. Txhawm rau kom tau txais cov khoom sib txawv, cov hlau tsis tshua muaj hauv ntiaj teb xws li Dy thiab Pr tuaj yeem hloov qee yam los ntawm CO, Al, thiab lwm yam. Cov ntsiab lus ntawm boron yog me me, tab sis hauv kev tsim cov tetragonal intermetallic compounds ua lub luag haujlwm tseem ceeb, uniaxial anisotropy thiab High Curie kub tau tham txog, muab cov compound high saturation magnetization thiab siab saturation magnetization. Nws yog ib qho ntawm cov hlau nplaum ua tau zoo tshaj plaws ua lag luam hu ua magneto thiab muaj cov khoom sib nqus siab heev. Nws cov khoom siv hluav taws xob sib nqus siab tshaj plaws yog ntau dua 10 npaug siab dua li ntawm ferrite. Nws cov kev ua tau zoo kuj zoo heev. Kev ua haujlwm kub tuaj yeem ncav cuag 240 degree. Ntxiv mus, nws muaj kev ntxhib los mos, kev ua haujlwm ruaj khov thiab kev ua haujlwm zoo, yog li nws tau siv dav.
Cov khoom tseem ceeb ntawm samarium cobalt hlau nplaum: Nws yog cov hlau nplaum ua los ntawm cov khoom siv hlau tsawg hauv ntiaj teb xws li samarium thiab cobalt. Cobalt hlau nplaum yog qhov thib ob loj tshaj plaws hlau nplaum tsim nyob rau hauv 1970. Nws muaj lub siab tshaj plaws magnetic zog khoom, siab coercive quab yuam, thiab yog yooj yim rau tawg thiab tawg. Nws yog qhov thib ob loj tshaj plaws sib nqus khoom niaj hnub no.
