SmMn₂Ge₂和GdMn₂Ge₂中的自发磁相变和场诱导的磁相变

来源期刊：中南大学学报(自然科学版)2000年第4期

论文作者：郭光华

文章页码：307 - 310

关键词：稀土金属间化合物;磁结构;磁相变;磁致伸缩

Key words：rare earth intermetallic compound; magnetic structure; magnetic phase transition; magnetostriction

摘    要：在10~800 K的温度范围内用X射线衍射方法测量了SmMn₂Ge₂和GdMn₂Ge₂的晶格常数与温度的变化关系.实验结果表明:在各种类型的自发磁相变温度处观察到晶格常数的磁弹性异常现象;Mn-Mn间的交换相互作用能不仅与晶格常数a有关,而且与晶格常数c有关.此外,在27 T的脉冲强磁场中测量了SmMn₂Ge₂及GdMn₂Ge₂的磁致伸缩,在这2种化合物中观察到了场诱导的一级磁相变.

Abstract: The temperature dependence of lattice constantsaandcof intermetallic compounds SmMn₂Ge₂ and GdMn₂Ge₂ is measured in the temperature range 10~800 Kby using the X-raymethod. The magnetoelastic anomalies of aandcare found at different spontaneous magnetic phase transitions. It is shown that theMn-Mn exchange interactions depend not only on the lattice constantabut also on constantc. The magnetostriction of SmMn₂Ge₂ and GdMn₂Ge₂ is measured in the 27 Tplus magnetic field. The field-induced magnetic phase transitions are found in these compounds.