DyxEr5－xSi3系列化合物晶体结构和磁性研究

Dy_xEr₅－_xSi₃系列化合物晶体结构和磁性研究

摘要: 利用电弧炉制备了DyxEr5－xSi3（x＝0，1，2，3，4，5）系列化合物样品。通过X射线粉末衍射分析和磁性测量研究了Dy替代Er对Er5Si3化合物晶体结构和磁性的影响。结果表明：DyxEr5－xSi3（x＝0，1，2，3，4，5）系列化合物的晶体结构为Mn5Si3型，随着Dy替代量的增加，晶胞体积变大。当0≤x≤2时，样品具有反铁磁性，顺磁居里温度由负值（x＝0）变为正值；而x＝3，4时，样品显现铁磁性，顺磁居里温度均为正值。虽然磁性原子及其相互作用的变化对磁性能影响很大，但所有样品的磁有序转变温度都很好地遵守了De Gennes定律。

Abstract: The crystal structures and magnetic properties of DyxEr5－xSi3 compounds were studied by X-ray powder diffraction and magnetic measurements. The main results show that the crystal structures of all DyxEr5－xSi3 (x＝0, 1, 2, 3, 4, 5) compounds are Mn5Si3 type with space group of P63/mcm. With Dy concentration increasing, the unit cell volumes increase. The magnetization curves apparently indicate that DyxEr5－xSi3 (x＝0, 1, 2) and DyxEr5－xSi3 (x＝3, 4) exhibit antiferromagnetic and ferromagnetic behavior respectively. The Weiss temperatures are positive except Er5Si3. Moreover, the magnetic ordering temperatures obey De Gennes’ law although the magnetic properties are affected by different magnetic atoms and the interaction among them.