Wang Jun, Duan Hongyan, Lin Xiong, Aguilar Victor, Mosqueda Aaron, Zhao Guo-Meng
J Appl Phys. 2012 Nov 15;112(10):103905. doi: 10.1063/1.4759352. Epub 2012 Nov 21.
Magnetic hysteresis loops were measured for ferrimagnetic iron chalcogenide [Formula: see text] nanoparticles in the whole temperature range below the Curie temperature [Formula: see text] (315 K). The coercivity of the material is huge, reaching about 40 kOe at 10 K. The magnetic anisotropy constant K was determined from the magnetic hysteresis loop using the law of approach to saturation. The deduced anisotropy constant at 10 K is [Formula: see text], which is over one order of magnitude larger than that of [Formula: see text]. We also demonstrated that the experimental magnetic hysteresis loop is in good agreement with the theoretical curve calculated by Stoner and Wohlfarth for a noninteracting randomly oriented uniaxial single-domain particle system. Moreover, we show that K is proportional to the cube of the saturation magnetization [Formula: see text], which confirms earlier theoretical models for uniaxial magnets.
在低于居里温度(T_C)（315 K）的整个温度范围内，测量了亚铁磁性硫族化铁([公式：见原文])纳米颗粒的磁滞回线。该材料的矫顽力很大，在10 K时达到约40 kOe。利用趋近饱和定律从磁滞回线确定了磁各向异性常数(K)。在10 K时推导出的各向异性常数为([公式：见原文])，比([公式：见原文])的各向异性常数大一个数量级以上。我们还证明，实验磁滞回线与斯托纳和沃尔法思为非相互作用随机取向单轴单畴粒子系统计算的理论曲线吻合良好。此外，我们表明(K)与饱和磁化强度([公式：见原文])的立方成正比，这证实了早期单轴磁体的理论模型。
