论文标题
Na0.5LA0.5RUO3钙钛矿的结构，磁和第一原理建模
Structure, Magnetism and First Principles Modeling of the Na0.5La0.5RuO3 Perovskite
论文作者
论文摘要
高纯度多晶Na0.5LA0.5RUO3通过固态方法合成，并通过磁敏感性，热容量和电阻率测量来研究其性能。与较早的报告相比，我们发现它是四方钙钛矿，并随机LA/NA混合。库里 - 维斯温度为-231 K，有效矩为2.74 Ub/mol-ru，没有磁性排序降至1.8 k。但是，热容量为1.4 k的宽阔驼峰，表明存在玻璃磁性转变，我们将Na和la的随机分布对perovskite的影响归因于perovskite a网站的随机分布的影响。与Caruo3进行了比较，Caruo3提出了一种结构有序的鲜烯酸钙钛矿具有相似特性。第一原则计算表明，Na-LA分布决定了RU离子之间的局部磁交换互换，当局部环境为Na或La富集时，有利于抗铁磁或铁磁耦合。因此，我们的数据和分析表明，该钙钛矿中A位置上用不同的电荷和尺寸混合阳离子通过平衡局部磁交换相互作用而导致磁性挫败感。
High purity polycrystalline Na0.5La0.5RuO3 was synthesized by a solid state method, and its properties were studied by magnetic susceptibility, heat capacity and resistivity measurements. We find it to be a tetragonal perovskite, in contrast to an earlier report, with random La/Na mixing. With a Curie-Weiss temperature of -231 K and effective moment of 2.74 uB/mol-Ru, there is no magnetic ordering down to 1.8 K. A broad hump at 1.4 K in the heat capacity, however, indicates the presence of a glassy magnetic transition, which we attribute to the influence of the random distribution of Na and La on the perovskite A sites. Comparison to CaRuO3, a structurally ordered ruthenate perovskite with similar properties, is presented. First-principle calculations indicate that the Na-La distribution determines the local magnetic exchange inter-actions between Ru ions, favoring either antiferromagnetic or ferromagnetic coupling when the local environment is Na or La rich. Thus our data and analysis suggest that mixing cations with different charges and sizes on the A site in this perovskite results in magnetic frustration through a balance of local magnetic exchange interactions.
