Centre for Theoretical Studies, Indian Institute of Technology, Kharagpur, India.
Phys Chem Chem Phys. 2018 Jul 4;20(26):17871-17880. doi: 10.1039/c8cp01500g.
It has been realized lately that disorder, primarily in the form of oxygen vacancies, cation stoichiometry, atomic inter-diffusion and antisite defects, has a major effect on the electronic and transport properties of a 2D electron liquid at oxide hetero-interfaces - the first and the last being the two key players. In order to delineate the roles of these two key factors, we have investigated the effect of oxygen vacancies on the antisite disorder at a large number of interfaces separating two La-based transition metal oxides, using density functional theory. The oxygen vacancy is found to suppress antisite disorder in some heterostructures thereby stabilizing the ordered structure, while in some others, it tends to favor disorder, opening up the possibility of using it to control the order. Our calculations show that the oxygen vacancy offers an opportunity to generate new magnetic states by manipulating the inter-site coupling. Moreover, it can be used to control the electrical transport. The oxygen vacancy and antisite disorder are intrinsic to oxide heterostructures and it is therefore incumbent to engineer the latter and tune the magnetic and transport properties by controlling the oxygen partial pressure during growth.
最近人们已经意识到，无序，主要以氧空位、阳离子化学计量比、原子互扩散和反位缺陷的形式，对氧化物异质界面上的 2D 电子液体的电子和输运性质有重大影响——前两个是两个关键因素。为了阐明这两个关键因素的作用，我们使用密度泛函理论研究了氧空位对两种基于镧的过渡金属氧化物之间大量界面上反位无序的影响。氧空位被发现可以抑制一些异质结构中的反位无序，从而稳定有序结构，而在另一些结构中，它倾向于有利于无序，从而为控制有序提供了可能性。我们的计算表明，氧空位通过操纵相间耦合提供了产生新磁态的机会。此外，它可用于控制电输运。氧空位和反位无序是氧化物异质结构固有的，因此有必要通过在生长过程中控制氧分压来设计后者并调整磁性和输运性质。
