Abstract We detected a crossover from negative to positive thermal expansion with increasing Mn in HoCo2Mnx below the Curie temperature through high quality neutron diffraction measurements from 5 K to 400 K. Almost isotropic zero thermal expansion with coefficient of thermal expansion αl = −4.894 × 10−7/K was achieved over a large range of temperature from 5 K to TC = 225 K in the compound HoCo2Mn0.5. While the addition of manganese was shown to change the temperature dependence of the lattice, it was also noted that the Curie temperature rose significantly from 88 K in HoCo2 to 253 K in HoCo2Mn providing a hope for a room temperature transition in similar doping series materials.

中文翻译：

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一系列设计的磁热材料 HoCo2Mnx (x = 0-1.0) 中的可控各向同性热膨胀

摘要 我们通过从 5 K 到 400 K 的高质量中子衍射测量检测到从负热膨胀到正热膨胀的交叉，在居里温度以下的 HoCo2Mnx 中 Mn 增加。几乎各向同性的零热膨胀，热膨胀系数 αl = -4.894 × 10−在化合物 HoCo2Mn0.5 中，在从 5 K 到 TC = 225 K 的大温度范围内实现了 7/K。虽然添加锰会改变晶格的温度依赖性，但也注意到居里温度从 HoCo2 中的 88 K 显着上升到 HoCo2Mn 中的 253 K，这为类似掺杂系列材料的室温转变提供了希望。