Cov khoom siv hlau nplaum ruaj khov yog siv dav hauv ntau lub zog hauv kev lag luam xws li tsheb, khoom siv hauv tsev, lub zog, tshuab, kev kho mob, thiab aerospace, nrog rau cov khoom sib txuas uas xav tau sib txawv muaj zog sib nqus. Cov khoom siv hlau nplaum tau txheeb ze rau txhua yam ntawm cov ntaub ntawv siv thev naus laus zis, kev siv tshuab, mechatronics, tiv thaiv lub teb chaws, thiab kev lag luam hauv teb chaws, thiab muaj qhov ua tsis tau zoo hauv ntau lub teb. Cov hlau nplaum cov khoom siv feem ntau yog Fe, Co, Ni ntsiab thiab lawv cov alloys, lub ntiaj teb tsis tshua muaj ntsiab lus thiab lawv cov alloys, thiab qee qhov Mn tebchaw. Cov ntaub ntawv hlau nplaum tau muab faib ua cov khoom sib nqus mos thiab cov khoom siv sib nqus muaj zog raws li qhov nyuaj ntawm lawv cov hlau nplaum. Ntawm lawv, cov hlau nplaum mos cov ntaub ntawv yooj yim kuj yooj yim rau magnetize thiab demagnetize piv rau cov khoom siv hlau nplaum ruaj khov. Lawv lub luag haujlwm tseem ceeb yog sib nqus permeability thiab electromagnetic Zog hloov dua siab tshiab thiab kis tau tus mob; cov ntaub ntawv sib nqus nyuaj tseem muaj lub npe hu ua cov hlau nplaum ruaj khov. Tom qab tau raug pom los ntawm lub chaw sib nqus sab nraud, txawm tias nyob hauv qhov kev txiav txim ntawm qhov rov qab ntau qhov chaw sib nqus, lawv tseem tuaj yeem tuav cov hlau nplaum ntawm ib lossis feem ntau ntawm cov thawj qhov kev qhia txog lub zog hlau nplaum, thiab muaj hluav taws xob teeb liab hloov dua siab tshiab, Lub zog hluav taws xob-kev siv lub zog hloov pauv yog dav siv nyob rau hauv ntau lub cev muaj zog hauv kev lag luam xws li tsheb, khoom siv hauv tsev, lub zog, tshuab, kho mob, aerospace thiab lwm yam kev lag luam, nrog rau cov khoom siv uas yuav tsum tau tsim kom muaj qhov sib txawv muaj zog sib nqus.
Cov khoom siv hlau nplaum tas li tuaj yeem raug faib ua peb pawg: lub ntiaj teb tsis tshua muaj hlau nplaum tas li, hlau nplaum ruaj khov thiab lwm cov hlau nplaum ruaj khov. Ntawm lawv, tsis tshua muaj lub ntiaj teb cov khoom siv hlau nplaum tas li tau txuas ntxiv txhim kho ntawm qhov kev kub ceev txij li xyoo 1960. Raws li lub sijhawm ua ntu zus ntawm lawv txoj kev txhim kho thiab daim ntawv thov, lawv tuaj yeem muab faib ua plaub tiam: thawj tiam yog RECo5 series cov khoom siv sawv cev los ntawm SmCo5; lub cim thib ob yog RECo17 series sawv cev los ntawm Sm2Co17 hlau nplaum; lub cim thib peb yog neodymium hlau boron (NdFeB) cov khoom siv hlau nplaum uas tau ua tiav zoo thaum xyoo 1980s. Vim tias nws yog Fe-based ntiaj teb cov khoom siv tsawg, nws muaj tus nqi qis dua thiab kev ua haujlwm zoo. Nws hloov sai sai RECo17 nyob rau hauv ntau daim teb Cov hlau nplaum yog tam sim no cov khoom siv dav siv hauv ntiaj teb cov hlau nplaum tsis tu ncua, thiab plaub tiam yog hlau-nitrogen (Re-Fe-N) thiab hlau-carbon (Re-Fe-C), uas yog tseem nyob rau theem kev txhim kho, lossis xav tau kaum ob ntawm Nws yuav siv sijhawm ntev heev los ua kom paub cov peev txheej loj thiab kev thov.