Statistics on the magnetism of cobalt compounds: A database approach to discovering new Co-based ferromagnets

Discovery of novel ferromagnetic materials can often be hampered by the lack of a comprehensive repository of magnetic data, and it can be easy to overlook the less well-known families of compounds. We propose a method to facilitate the search for novel ferromagnets by creating a database of cobalt-based compounds. Based on a comprehensive literature survey of the magnetic properties of compounds with more than 33 at. % Co, we classify more than 13,000 compounds by structure types, cobalt content, ordering type and temperature, and easy magnetization direction. We focus our analysis on data trends of Curie temperatures, structure families favoring ferromagnetism, and uniaxial anisotropy. We identify compounds TaCo₂Ga, La₆Co₁₃Bi, and Nd₂Co₃ as potential ferromagnets, and use first-principles calculations and experimental synthesis and measurements to confirm their magnetic properties. From the subset of known ferromagnets with unknown anisotropy, we select the compound MgCo₂ as potentially having uniaxial magnetic anisotropy at room temperature, which we also confirm experimentally.

Reference: J. K. Byland, Y. Shi, D. S. Parker, J. Zhao, S. Ding, R. Mata, H. E. Magliari, A. Palasyuk, S. L. Bud'ko, P. C. Canfield, P. Klavins, and V. Taufour, Phys. Rev. Materials 6, 063803 (2022)