Nykwest Erik C, Alpay S P
Department of Physics, University of Connecticut, Storrs, CT 06269, United States of America.
J Phys Condens Matter. 2019 Jun 19;31(24):245801. doi: 10.1088/1361-648X/ab0fe4. Epub 2019 Mar 14.
Judicious doping of normally diamagnetic alumina (AlO) could lead to bulk magnetism that would enable the usage of cutting edge technology, such as magnetoforming, to create advanced systems that take advantage of the high chemical and physical resilience of alumina. This study builds upon initial results (Nykwest et al 2018 J. Phys.: Condens. Matter 30 395801) which have shown that alumina doped with magnetic elements such as Fe and Ni should exhibit heightened magnetic activity. Here we expand the analysis to several additional transition metals that are otherwise non-magnetic (Sc, Ti, V, Mn, and Co) and use density functional theory to understand the origin of the spin delocalization, as well as to predict the structural, electronic, energetic, and magnetic properties of doped [Formula: see text]-alumina. The results indicate that adding small concentrations of such elements to [Formula: see text]-alumina may increase magnetic activity by generating coordination environments with magnetic moments. Our findings show conclusively that significant spin delocalization can only occur when there are unpaired electrons in the transition metal e states.
对通常呈抗磁性的氧化铝(AlO)进行明智的掺杂可能会导致体磁性,这将使诸如磁成型等前沿技术得以应用,从而创建利用氧化铝高化学和物理弹性的先进系统。本研究基于初步结果(Nykwest等人,2018年,《物理学杂志:凝聚态物质》30卷,395801),该结果表明掺杂有铁和镍等磁性元素的氧化铝应表现出增强的磁活性。在此,我们将分析扩展到其他几种原本无磁性的过渡金属(钪、钛、钒、锰和钴),并使用密度泛函理论来理解自旋离域的起源,以及预测掺杂的[化学式:见原文]-氧化铝的结构、电子、能量和磁性性质。结果表明,向[化学式:见原文]-氧化铝中添加少量此类元素可能会通过产生具有磁矩的配位环境来增加磁活性。我们的研究结果确凿地表明,只有当过渡金属e态存在未成对电子时,才会发生显著的自旋离域。