Cov duab anisotropy ntawm cov hlau nplaum ruaj khov nrog qee cov duab (tsis yog kheej kheej) muaj feem xyuam rau qhov demagnetic teb ntawm cov hlau nplaum ruaj khov.
Raws li paub rau txhua tus, N thiab S ncej yuav ib txwm tshwm sim nyob rau hauv ib qho thaiv lossis cylindrical ruaj khov hlau nplaum lub cev, thiab muaj cov hlau nplaum sib nqus yuav tsim cov hlau nplaum nyob ib puag ncig thiab hauv cov hlau nplaum. Cov hlau nplaum tsim los ntawm cov hlau nplaum ruaj khov ib txwm khiav ntawm N ncej mus rau S ncej, ob qho tib si nyob ib puag ncig thiab sab hauv cov hlau nplaum. Lub teb demagnetization hauv cov hlau nplaum ruaj khov yog sawv cev los ntawm Hd, thiab nws cov kev taw qhia yog los ntawm N ncej mus rau S ncej. Kev taw qhia ntawm lub sijhawm sib nqus ntawm cov hlau nplaum ruaj khov, Mm, lossis kev taw qhia ntawm kev sib nqus, yog los ntawm S ncej mus rau N ncej. Lub Hd nyob rau hauv cov hlau nplaum ruaj khov yog rov qab rau cov kev taw qhia ntawm cov hlau nplaum M thiab ua lub luag haujlwm ntawm demagnetization, yog li nws yog hu ua demagnetization teb.
The demagnetic field intensity of permanent magnet is related to the shape and size of permanent magnet. For example, for a circular permanent magnet, the demagnetic field intensity varies with the gap size of the circular permanent magnet (i.e. the length of the permanent magnet). When it is magnetized along the axis of the circular permanent magnet ring, no demagnetizing field is generated. When half of the circular permanent magnet is cut off, the demagnetic field of the half ring is Hd. The shorter a circular permanent magnet is cut, the greater the absolute value of its demagnetic field Hd. The increasing sequence of the absolute value of the demagnetization field is Hd (e)> Hd (d) >Hd (c) >Hd (b) >Hd (a) → 0.
Nws tuaj yeem suav hais tias yog thaum lub coercivity ntawm cov hlau nplaum ruaj khov Hcj tsis loj txaus, yog tias cov hlau nplaum ruaj khov yog ua nyias thiab sib nqus raws cov kev taw qhia nyias, nws yuav tsis tau sau vim tias qhov demagnetizing loj dhau.