Crystal Dynamics and Magnetic Excitations in Cobaltous Oxide
Crystal Dynamics and Magnetic Excitations in Cobaltous Oxide
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氧化钴中的晶体动力学和磁激发
DOI：
10.1103/physrev.167.510
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发表时间：
1968
期刊：
影响因子：
--
通讯作者：
G. Dolling
中科院分区：
文献类型：
--
作者：
J. Sakurai;W. Buyers;R. Cowley;G. Dolling
从实验和理论上研究了CoO在反铁磁有序温度以上和以下的低激发态。实验是在三轴晶体谱仪的辅助下，利用慢中子非弹性散射技术进行的。这些实验是困难的，因为声子和磁激发具有非常相似的频率，也因为样品具有反铁磁相的畴结构。然而，模型得到的声子谱。将CoO中Co2+的自旋轨道耦合参数降低到自由离子值的40%，就可以理解顺磁相的磁谱。有了这个值，就有可能通过引入最近邻和次最近邻交换参数来至少以定性的方式理解反铁磁相中的激发。由于研究实验部分遇到的困难，不可能对这种磁激励理论进行详细评估;尽管如此，人们相信这里给出的描述基本上是正确的。
The low-lying phonon and magnetic excitations of CoO have been studied experimentally and theoretically, both above and below the antiferromagnetic ordering temperature. The experiments were performed using the technique of inelastic scattering of slow neutrons with the aid of a triple-axis crystal spectrometer. These experiments were difficult because the phonon and magnetic excitations have very similar frequencies, and also because the specimen has a domain structure in the antiferromagnetic phase. Nevertheless, models were obtained for the phonon spectra. The magnetic spectra of the paramagnetic phase can be understood if the spin-orbit coupling parameter of Co 2+ of CoO is reduced to 40% of its free-ion value. With this value it is then possible to understand the excitations in the antiferromagnetic phase in at least a qualitative way by introducing nearest-and next-nearest-neighbor exchange parameters. A detailed evaluation of this theory of the magnetic excitations is not possible, because of the difficulties encountered in the experimental part of the study; nevertheless, it is believed that the description given here is essentially correct.