Atomistic simulation of Mn-site substitution in multiferroic h-YMnO3
Atomistic simulation of Mn-site substitution in multiferroic h-YMnO3
复制标题
DOI：
10.1088/0953-8984/24/23/235402
复制
发表时间：
2012-06
期刊：
影响因子：
--
通讯作者：
N. Jiang;X. Zhang
中科院分区：
文献类型：
--
作者：
N. Jiang;X. Zhang
采用原子模拟的方法系统地研究了六方钇锰氧化物（h-YMnO3）的mn位掺杂。发现四价掺杂剂在能量上最有利于掺入晶格中。对于二价掺杂剂，空穴补偿是更可能的电荷补偿机制，而对于混合价掺杂剂，二价态是能量上的首选形式。研究了mn位掺杂引起的结构和局部极化变化。在所研究的所有掺杂剂中，MnO5三角双棱锥的倾斜角都受到抑制，其倾斜角的减小取决于掺杂剂的离子半径，而对屈曲的影响与掺杂剂的价态密切相关。结果表明，静电效应和尺寸效应在h-YMnO3的铁电极化中起重要作用。
Atomistic simulation has been performed to systematically investigate the Mn-site doping of h-YMnO3 (hexagonal yttrium manganese oxide). It is found that tetravalent dopants are the most energetically favorable for incorporation into a crystal lattice. For divalent dopants, hole compensation is the more likely charge compensation mechanism, whereas for dopants with mixed valence, the divalent state is the energetically preferred form. Structural and local polarization changes caused by Mn-site doping are also investigated. The tilting angle of the MnO5 trigonal bipyramid is suppressed for all of the dopants investigated, with the reduction dependent on the dopant ion radius, while the influence on buckling is closely related to the valence of the dopants. Our results reveal that both electrostatic and size effects play important roles in the ferroelectric polarization of h-YMnO3.