Abstract

In this paper, the results of investigating thin films of rare-earth helimagnetics (REMs) Dy and Ho by polarized neutron reflectometry are presented. It is shown that the growth by magnetron sputtering of rare-earth structures on sapphire substrates with a buffer layer Nb \(\left[ {1\bar {1}02} \right]\) Al₂O₃||[110]Nb||\(\left[ {0001} \right]R\) leads to complete relaxation of the Nb crystal lattices and the rare-earth film. It is found that some magnetic phase transitions typical of bulk Dy and Ho are not observed in 200 nm [0001]R thin films or are observed in a modified form. Differences between the Néel and Curie temperatures of thin REM films compared to bulk REMs are determined based on polarized-neutron-reflectometry data and measurements of the temperature dependence of the magnetization in the sample plane.

中文翻译：

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用中子反射法研究 Dy 和 Ho 薄膜中的 Helimagnetism

摘要

在本文中，介绍了通过偏振中子反射法研究稀土螺旋磁体 (REM) Dy 和 Ho 薄膜的结果。结果表明，在具有缓冲层 Nb \(\left[ {1\bar {1}02} \right]\) Al ₂ O ₃ ||[110] 的蓝宝石衬底上通过磁控溅射生长稀土结构铌|| \(\left[ {0001} \right]R\)导致 Nb 晶格和稀土薄膜的完全弛豫。发现在 200 nm [0001] R中没有观察到一些典型的体 Dy 和 Ho 的磁性相变薄膜或以改性形式观察。与体 REM 相比，REM 薄膜的 Néel 和居里温度之间的差异是基于极化中子反射数据和样品平面中磁化强度的温度依赖性测量来确定的。