SPIN-WAVE DISPERSION CURVES FOR YTTRIUM IRON-GARNET
SPIN-WAVE DISPERSION CURVES FOR YTTRIUM IRON-GARNET
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DOI：
10.1088/0022-3719/10/23/014
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发表时间：
1977-01-01
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影响因子：
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通讯作者：
PLANT, JS
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作者：
PLANT, JS
用中子三轴谱技术测量了Y3 Fe 5 O 12在居里-尼尔温度560 K以下的激发分支。一个陡峭的光学分支福尔斯随着温度稳定下降，表现在长波长像这个亚铁磁体的自发力矩，而声能保持在一个容易的方向111赫兹的磁化低得惊人。低温下的测量结果与Brinkman和Elliott（1966）基于自旋波线性理论的计算结果基本一致，其中假定Fe自旋矩对之间的相互作用为典型值5 J 1aa= 5 J 1dd= J 1ad=-40 K：剩余的差异可以归因于进一步的相互作用，如J 2aa和磁振子与声子的耦合。
A number of excitation branches have been measured by neutron triple-axis spectrometry techniques for Y 3 Fe 5 O 12 below its Curie-Neel temperature 560K. A steep optic branch falls steadily with temperature, behaving at long wavelengths like the spontaneous moment of this ferrimagnet, whilst acoustic energies remain anomalously low for an easy direction⟨ 111⟩ of magnetisation. Low-temperature measurements agree approximately with some calculations of Brinkman and Elliott (1966) based on a linear theory of spinwaves, when typical values 5J 1aa= 5J 1dd= J 1ad=-40K are assumed for interactions between pairs of Fe spin-moments: remaining discrepancies can be attributed to further interactions such as J 2aa and a coupling of magnons and phonons.