论文标题
MGCR $ _2 $ o $ _4 $尖晶石薄膜的方向依赖于稳定
Orientation-dependent stabilization of MgCr$_2$O$_4$ spinel thin films
论文作者
论文摘要
AB $ _2 $ o $ _4 $带有磁性B位点的普通尖晶石可以容纳各种磁性和轨道挫败感，从而导致旋转液体相和野外诱导的相变。在这里，我们报告了（111）面向的MGCR $ _2 $ o $ _4 $薄膜的第一个外延增长。通过表征沿（001）和（111）方向生长的膜的结构和电子特性，已经研究了生长取向的影响。尽管在沉积过程中观察到了明显不同的生长模式，但全面的特征表明，阳离子分布中没有可测量的障碍，也没有针对任何方向的CR离子的多价问题。与幼稚的期望相反，（111）稳定膜表现出比（001）面向的薄膜更平滑的表面和更高的结晶度。在杂质稳定稳定框架内解释了生长取向的偏好，这与明显较低（111）的表面能有关。这些发现在制造2D kagome三角形异质结构中，在散装晶体中无法访问的磁性不可接近。
AB$_2$O$_4$ normal spinels with a magnetic B site can host a variety of magnetic and orbital frustrations leading to spin-liquid phases and field-induced phase transitions. Here we report the first epitaxial growth of (111)-oriented MgCr$_2$O$_4$ thin films. By characterizing the structural and electronic properties of films grown along (001) and (111) directions, the influence of growth orientation has been studied. Despite distinctly different growth modes observed during deposition, the comprehensive characterization reveals no measurable disorder in the cation distribution nor multivalency issue for Cr ions in either orientation. Contrary to a naive expectation, the (111) stabilized films exhibit a smoother surface and a higher degree of crystallinity than (001)-oriented films. The preference in growth orientation is explained within the framework of heteroepitaxial stabilization in connection to a significantly lower (111) surface energy. These findings open broad opportunities in the fabrication of 2D kagome-triangular heterostructures with emergent magnetic behavior inaccessible in bulk crystals.
