利用固相反应法制备了用Sr部分替换GdMnO3中Gd的锰基钙钛矿氧化物Gd0.7Sr0.3MnO3.X射线衍射表明其晶体结构为正交晶系,空间群为Pnma.通过测量样品在零场冷却和加场冷却下的磁化强度及磁化率随温度的变化曲线,得出样品显示亚铁磁特性,Mn和Gd两个子晶格相互反平行.根据居里-外斯定律得知其居里温度为61 K,Mn原子轨道磁矩对总磁矩贡献大约为1.04μB.最大外加磁场为7000 Oe时负磁熵变从-0.26 J/Kg K连续变化到0.22 J/Kg K,在37 K附近磁熵变近似等于零.
The gadolinium-based manganite GdMnO3,partially substituted by strontium at the cationic site,has been investigated through its crystallochemical and magnetic properties.The Gd0.7Sr0.3MnO3 powder sample crystallises in an orthorhombic perovskite-type structure（S.G.Pnma）.Field Cold and Zero Field Cold measurements show that the powder sample can be described as a ferrimagnetic system.The Mn sublattice and the Gd sublattice are antiparallel each other,because of negative exchange interaction.According to Curie-Weiss law the Curie temperature is 61K,and the Mn ion contributes 1.04μB orbital moment to the total magnetization.The-ΔSM changes from-0.26J/Kg K to 0.22J/Kg K continually and almost to zero around 37K,at which measurements the maximum applied field is 7,000 Oe.
参考文献
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| [2] | 郭焕银,彭振生,蔡之让,刘宁.A位的Gd掺杂对La0.7-xGdxSr0.3MnO3体系磁结构的影响[J].无机材料学报,2005(03):647-652. |
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