论文标题
Sr $ _ {1-x} $ ba $ _ {x} $ mno $ _3 $的磁和铁电特性
Magnetic and ferroelectric properties of Sr$_{1-x}$Ba$_{x}$MnO$_3$ from first principles
论文作者
论文摘要
密度功能理论（DFT）计算用于研究Sr $ _ {1-X} $ BA $ _ {X} $ MNO $ _3 $的磁性和铁电特性，重点放在$ x = 0.5 $上，在等型体积膨胀/压缩/压缩和生物菌株下。我们的结果表明，出乎意料的是，BA取代以一种在固定晶格参数下的方式改变了电子结构，特别是增强了原子质磁交换的相互作用。但是，增加的BA含量也会导致体积膨胀，从而降低这些相互作用，从而导致弱抑制磁性的净作用，如实验中所观察到的那样。另一方面，发现铁电特性受电子结构变化的影响较小，并且可以在很大程度上可以从BA-ba-substitution引起的体积膨胀方面理解。计算出的电力极化是Sr $ _ {1-x} $ ba $ _ {x} $ mno $ _3 $的双轴应变的函数，$ x = 0 $ x = 0 $ and $ x = 0.5 $，表明两者之间的差异主要是由于某些应变值在某些应变值上的差异，伴随着大量的Magnetoelecto couletrorcrectrorceplorceplorceplorce couletrorceplorceplorceplorceplorce couletrorceplect。
Density functional theory (DFT) calculations are used to study the magnetic and ferroelectric properties of Sr$_{1-x}$Ba$_{x}$MnO$_3$, with focus on $x=0.5$, under isotropic volume expansion/compression and biaxial strain. Our results indicate that, unexpectedly, Ba substitution alters the electronic structure in a way that, at fixed lattice parameter, notably enhances the interatomic magnetic exchange interactions. However, increasing Ba-content also causes a volume expansion which tends to weaken these interactions, leading to a net effect of weakly suppressed magnetism, as observed in experiments. The ferroelectric properties, on the other hand, are found to be less affected by changes in the electronic structure and can largely be understood in terms of the volume expansion caused by Ba-substitution. The calculated electric polarization as a function of biaxial strain in Sr$_{1-x}$Ba$_{x}$MnO$_3$ for $x=0$ and $x=0.5$, shows that the difference between the two is mainly due to differences in the magnetic order at certain strain values, accompanied by enormous magnetoelectric coupling.
