Towards magnetic alumina: uncovering the roles of transition metal doping and electron hybridization in spin delocalization

• Published in: Journal of physics. Condensed matter Vol. 31; no. 24; p. 245801
• Main Authors: Nykwest, Erik C, Alpay, S P
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 19.06.2019
• Subjects: alumina; density functional theory; electronic density of states; magnetic response; spin delocalization; spin density; transition metal doping
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/1361-648X/ab0fe4

Judicious doping of normally diamagnetic alumina (Al2O3) 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 -alumina. The results indicate that adding small concentrations of such elements to -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 eg states.