Magnetic Anisotropy of Cobalt Ferrite (Co1.01Fe2.00O3.62) and Nickel Cobalt Ferrite (Ni0.72Fe0.20Co0.08Fe2O4)
Magnetic Anisotropy of Cobalt Ferrite (Co1.01Fe2.00O3.62) and Nickel Cobalt Ferrite (Ni0.72Fe0.20Co0.08Fe2O4)
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DOI：
10.1103/physrev.107.1246
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发表时间：
1957-09
期刊：
影响因子：
--
通讯作者：
H. Shenker
中科院分区：
文献类型：
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作者：
H. Shenker
本文提出了一种测量立方晶体第一磁各向异性常数K1的方法，该方法利用了在易磁化方向附近测量磁场方向的转矩。在20 ~ 325 K范围内，钴铁氧体晶体的K1与经验关系式K1 = 19.6× 106 exp（− 1.90× 10− 5 T2）ergs/cc非常接近。在325以上，测得的各向异性取决于晶体在磁场中的时间长度。对于镍钴铁氧体晶体，用通常的扭矩法测量的K1经验地由K1 =[8.08exp（− 3.57× 10− 5 T 2）− 9.78 exp（-0.863 × 10-5T2）]× 104 ergs/cc，而K2在20.5时从-4.7× 104 ergs/cc增加，在190时通过零，在280 K时，温度上升到1× 104，然后迅速下降到零。K 1的关系式与Brükhatov和Kirensky在金属铁磁材料中发现的关系式具有相同的形式。
A method of measuring the first magnetic anisotropy constant, K 1, of cubic crystals having a large anisotropy was developed which utilized measurements of the torque for directions of the applied field near the direction of easy magnetization. By this method K 1 of a cobalt ferrite crystal was found to be closely approximated by the empirical relationship K 1= 19.6× 10 6 exp (− 1.90× 10− 5 T 2) ergs/cc from 20 to 325 K. Above 325 the measured anisotropy depended upon the length of time the crystal was in the magnetic field. For a nickel cobalt ferrite crystal, K 1, as measured by the usual torque method, was given empirically by K 1=[8.08 exp (− 3.57× 10− 5 T 2)− 9.78 exp (− 0.863× 10− 5 T 2)]× 10 4 ergs/cc from 20 to 600 K while K 2 increased from-4.7× 10 4 ergs/cc at 20.5, passed through zero at 190, rose to a maximum of 1× 10 4 at 280 K, and then above this temperature decreased rapidly to zero. The relationships for K 1 are of the same form as those found by Brükhatov and Kirensky for metallic ferromagnetic materials.