arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1303.1908cond-mat.str-el
收藏

SmIr2Si2多晶型体对称性对Sm磁性的影响

Influence of symmetry on Sm magnetism studied on SmIr2Si2 polymorphs

Michal Vališka, Jiří Pospíšil, Jan Prokleška, Martin Diviš, Alexandra Rudajevová, Ilja Turek, Vladimír Sechovský

摘要:

SmIr2Si2多晶样品在室温下形成低温相(LTP)和亚稳高温相(HTP),分别取决于热处理。通过X射线粉末衍射、差热分析、比热容和磁场测量对样品进行了研究。一级LTP到HTP的多晶相变表明,在相变过程中,由于Sm、Ir和Si基平面片层的堆叠变化,导致了高能垒,从而导致了264°C的巨大温度滞后。这两种多晶型物在低温下显示出反铁磁有序的迹象。相当不同的磁性相变确定的LTP和HTP证实了强烈的影响,晶体结构对称性的磁性在两个多晶型。SmIr2Si2的磁性表现出典型的由Sm 3+离子的特殊行为引起的特征,表现为基态和第一激发态的能量接近性以及晶场的影响。实验结果的解释证实了从头计算的电子结构计算结果。

英文摘要:

Polycrystalline samples of SmIr2Si2 formed at room temperature both the low temperature phase (LTP) and the metastable high temperature phase (HTP), respectively, depending on the heat treatment. The samples were studied by X-ray powder diffraction, DTA, specific-heat and magnetization measurements with respect to temperature and magnetic field. The first order LTP to HTP polymorphic phase transition has been determined showing the huge temperature hysteresis of 264°C caused by the high energy barrier due to the change of stacking of Sm, Ir and Si basal plane sheets within the transition. Both polymorphs show indications of antiferromagnetic order at low temperatures. The considerably different magnetic phase transitions determined for the LTP and HTP confirm the strong influence of crystal structure symmetry on magnetism in the two polymorphs. The magnetism in SmIr2Si2 exhibits typical features caused by the specific behavior of Sm3+ ion characterized by energy nearness of the ground state and first excited state and crystal field influence. Interpretation of experimental results is corroborated by results of ab initio electronic structure calculations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑