Manipulation of spin-flip in Co.sub.3O.sub.4: a first principles study

• Published in: Journal of materials science 2016-05, p.4691
• Main Authors: Wu, Mu-Sheng, Xu, Bo, Ouyang, Chu-Ying
• Format: Article
• Language: English
• Subjects: Spinel group
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-016-9786-x

Manipulation of spin-flip is important in spintronics applications. In this paper, we report a simple manipulation of three Co-3d spin states in the Co.sub.3O.sub.4 spinel. From first principles calculations, we demonstrate that the spin state of Co atoms at octahedral sites (Co.sup.oct) of the Co.sub.3O.sub.4 spinel can be manipulated through tensile stains. The magnetic moment of the Co.sup.oct changes from the ground non-magnetic (0 µ.sub.B) state to the intermediate-spin state (2 μ.sub.B) and high-spin state (4 μ.sub.B) when 5 % (or higher) uniaxial tensile strain and 3 % (or higher) biaxial tensile strain are applied to the lattice, respectively. Moreover, the mechanism of the spin state transition of the Co-3d electrons in Co.sub.3O.sub.4 is discussed, and we show that the occurrence of spin-flip is a result of the competition between the cubic crystal field energy and the exchange correlation energy. These results open a new route to achieve and manipulate triple-spin states in spintronic devices.