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arXiv · 1704.04514

Structures, phase transitions, and magnetic properties of Co3Si from first-principles calculations

Xin Zhao·Shu Yu·Shunqing Wu·Manh Cuong Nguyen·Cai-Zhuang Wang·Kai-Ming Ho
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Abstract

Co3Si was recently reported to exhibit remarkable magnetic properties in the nanoparticle form [Appl. Phys. Lett. 108, 152406 (2016)], yet better understanding of this material is to be promoted. Here we report a study on the crystal structures of Co3Si using adaptive genetic algorithm, and discuss its electronic and magnetic properties from first-principles calculations. Several competing phases of Co3Si have been revealed from our calculations. We show that the hexagonal Co3Si structure reported in experiments has lower energy in non-magnetic state than ferromagnetic state at zero temperature. The ferromagnetic state of the hexagonal structure is dynamically unstable with imaginary phonon modes and transforms to a new orthorhombic structure, which is confirmed by our structure searches to have the lowest energy for both Co3Si and Co3Ge. Magnetic properties of the experimental hexagonal structure and the lowest-energy structures obtained from our structure searches are investigated in detail.

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Xin Zhao, Shu Yu, Shunqing Wu, Manh Cuong Nguyen, Cai-Zhuang Wang, Kai-Ming Ho. 2017-04-14. Structures, phase transitions, and magnetic properties of Co3Si from first-principles calculations. https://doi.org/10.1103/physrevb.96.024422

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