Abstract

The interaction of weakly nonequilibrium phonons with the low-energy paramagnetic excitations of the rare-earth ions of the yttrium series in rare-earth garnet solid solutions is studied at liquid-helium temperatures. The interaction of nonequilibrium phonons with the low-energy excitations of Ho³⁺ and Tb³⁺, which are caused by local electric fields in a crystal lattice, is experimentally investigated. In the row of Kraemrs ions (where the nature of low-energy excitations is caused by the splitting of the ground level of a paramagnetic ion due to the local magnetic fields of neighboring ions), interaction in the nonequilibrium phonon–low-energy excitation system is only detected in the Er-containing solid solutions and is absent in the structures containing Gd³⁺, Dy³⁺, and Yb³⁺ rare-earth ions. In the two-level system model, the efficiency of interaction and the transport characteristics of thermal phonons are shown to depend on the type of rare-earth ion, the energy and spectral features of two-level systems, the moments of electrons in the 4f shell, and spin–lattice relaxation.

中文翻译：

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石榴石固溶体晶体中类似于肖特基的低能顺磁激发的声子光谱

摘要

在液氦温度下研究了弱非平衡声子与稀土石榴石固溶体中钇系列稀土离子的低能顺磁激发的相互作用。实验研究了非平衡声子与Ho ³⁺和Tb ³⁺的低能激发的相互作用，这是由晶格中的局部电场引起的。在Kraemrs离子行中（低能量激发的性质是由于相邻离子的局部磁场导致顺磁离子的地平面分裂而引起的），在非平衡声子-低能量激发系统中发生相互作用仅在含Er的固溶体中检测到，而在含Gd ³⁺的结构中不存在，Dy ³⁺和Yb ³⁺稀土离子。在两能级系统模型中，相互作用的效率和热声子的传输特性显示出取决于稀土离子的类型，两能级系统的能量和光谱特征，4个电子的矩f壳，旋转晶格弛豫。