氢化对HoCu2化合物结构和磁性的影响

研究了氢化对磁性蓄冷材料HoCu2结构和磁性的影响。结果表明，HoCu2化合物吸氢后可以形成保持HoCu2化合（CeCu2型）结构不变的氢化物HoCu2Hx、或者形成具有HoH2和Cu两相结构的材料以及形成具有HoCu2Hx，HoH2，Cu三相结构的材料。氢化物HoCu2Hx的品格常数变化较小，氢含量最大的HoCu2H3.04的品格体膨胀率仅为2．27％，HoCu21-H3.04的磁性与HoCu2相比基本不变。具有HoH2和Cu两相结构的样品及具有HoCu2Hx，HoH2，Cu三相结构的样品在5K时具有磁有序结构，但是温度降到5K都未观察到磁性相变，这些材料有可能作为在5K下使用的磁性蓄冷材料。

Hydrogen Induced Structural and Magnetic Transformations in HoCu2

The structure and magnetic properties of HoCu2 compound after hydrogenation were investigated. The results show that crystalline hydride HoCu2Hx, lattice distorted hydrides and a mixture of the two hydrides can be obtained by hydrogenation. HoCu2Hx remain the same structure as the matrix. HoCu2H3O4 arrives the maximal hydrogen content, accompanied only by 2.27% lattice expansion, and its magnetic properties almost remain constant compared to the matrix. Lattice distorted hydride is a mixture consisted of lattice distorted HoH2 and Cu. The magnetic results show that lattice distorted hydrides sample 4 and the mixture of crystalline hydride and lattice distorted hydride have a magnetic ordering structure at 5 K, but the magnetic phase transitions were not observed when the temperature dropped to 5 K.