项目名称: 部分填充方钴矿化合物的磁性机理研究
项目编号: No.11247020
项目类型: 专项基金项目
立项/批准年度: 2013
项目学科: 物理学II
项目作者: 朱丽娅
作者单位: 三峡大学
项目金额: 20万元
中文摘要: 在方钴矿化合物的晶格孔洞中填入稀土元素,形成填充方钴矿材料。填充元素的不同会改变体系的电子结构,进而影响其磁性质和输运性质。当形成部分填充方钴矿化合物时,填充量的不同以及填充位置的无序能调节体系的能带结构和价电子数,对总磁矩和磁转变临界温度都产生影响。从理论上研究部分填充方钴矿化合物中各种微观相互作用对体系磁性质的影响,有助于探明其中的磁性机理。本项目从典型的磁性Eu填充方钴矿体系EuyCo4Sb12着手,结合第一性原理和模型Hamiltonian两种方法,从其电子结构的特点出发,对照已有实验结果,对体系中各种相互作用、温度、外磁场等因素进行分析,计算磁矩、磁化率等磁学物理量,研究填充量以及填充位置无序的程度对体系磁矩和磁转变临界温度的影响,探索其中磁有序的起源,并进一步推广到其它稀土填充方钴矿化合物,加深对这类材料基本物理性质的认识。
中文关键词: 无序;磁性质;量子相变;熵;
英文摘要: Filling varied rare-earth atoms into the skutterudites may change the electronic structure of the system, and therefore the magnetic and transport properties.The total magnetic moment and the critical temperature above which the magnetization disappears are usually influenced by filling fraction and the filler disordering which will modulate the band structure and the number of valence electrons. Investigating the influences of the various interaction in the system may gain a clearer understanding of the magnetism in partially filled skutterudites. Beginning with the Eu-filled skutterudite EuyCo4Sb12 which shows a typical ferromagnetic behavior, the electronic structure, the interaction between the conduction electrons and the local spins of Eu ions will be investigated. The first-principles calculation and the interaction Hamiltonian model will be used in our investigations. The magnetic moment, magnetic susceptibility and other magnetic quantities will be calculated with changing the temperature and the magnetic field. The influences of the filling fraction and the filler disordering on the magnetic properties will be studied. Further investigations on other rare-earth filled skutterudites will be carried out to explore the magnetism in the partially filled skutterudites.
英文关键词: disorder;magnetism;quantum phase transition;entropy;