Energy of system of magnetic dipoles is(adsbygoogle = window.adsbygoogle || []).push({});

##E_H=-\mu_0 \vec{\mu}\cdot \vec{H}=-\mu_0\mu_zH##

why sign ''-''?

and ##\mu_z=-g_J\mu_Bm##

Again why ''-'' sign ?

##z## is choosen to be quantization direction, and along that direction is applied field ##H##.

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# Paramagnetism of Free Ions. Sign problem.

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