Raman scattering studies of hexagonal rare-earth RMnO3 (R = Tb, Dy, Ho, Er) thin films
Raman scattering studies of hexagonal rare-earth RMnO3 (R = Tb, Dy, Ho, Er) thin films
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DOI：
10.1002/jrs.2925
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发表时间：
2011-09-01
影响因子：
2.5
通讯作者：
Yang, In-Sang
中科院分区：
文献类型：
--
作者：
Nguyen Thi Minh Hien;Oh, Su-Young;Yang, In-Sang
利用拉曼散射光谱研究了六方晶系RMnO_3（R = Tb，Dy，Ho，Er）薄膜的声子和磁振子散射随稀土元素（R）的变化。我们发现，随着R的离子半径从Tb减小到Er，声子向更高的能量移动。结果表明，当R的离子半径减小时，六方RMnO 3的晶格常数a和c都会减小，并且晶格常数c对R的依赖性较弱。磁振子也转移到更高的能量时，半径的R离子减少，他们表现出更快的上移比声子。此外，Neel温度随R离子半径的减小也呈现出系统性的升高行为。稀土R对磁振子和Neel温度的依赖性可以通过Mn-Mn距离减小时自旋交换积分的快速增加来解释。版权所有（C）2011约翰威利父子有限公司
We have studied the rare-earth (R) dependence of the phonon and magnon scattering in hexagonal RMnO3 (R = Tb, Dy, Ho, Er) thin films using Raman scattering spectroscopy. We found, as the ionic radius of R decreases from Tb to Er, the phonons shift to higher energies. Our results indicate that both the lattice constants a and c of hexagonal RMnO3 would decrease when the ionic radius of R decreases, and the lattice constant c would have a weaker R dependence. The magnons also shift to higher energies when the radius of the R ion decreases, and they show faster upshift than the phonons. In addition, the Neel temperature also shows a systematic increasing behavior when the radius of the R ion decreases. The dependence of the rare-earth R on the magnons and the Neel temperature can be explained by the rapid increase of the spin-exchange integral when the Mn-Mn distance decreases. Copyright (C) 2011 John Wiley & Sons, Ltd.