Synthesis, Stability, and Magnetic Properties of Antiperovskite Co3PdN

Experimental synthesis and characterization of theoretically predicted compounds are important steps in the materials discovery pipeline. Here, we report on the synthesis of Co₃PdN, which was recently predicted to be a stable magnetic antiperovskite. The Co₃PdN thin films were grown by reactive sputtering and were confirmed to form in an antiperovskite crystal structure. The thermal stability of the compound is demonstrated up to 600 K by in situ X-ray diffraction, though the phase persists at slightly higher temperatures (700 K) in an air-free magnetometer. Both ab initio calculations and magnetization measurements find Co₃PdN to be ferromagnetic with an experimentally determined Curie temperature of T_C = 560 ± 5 K. The saturation magnetization of 1.2 μ_B/Co found in the experiment is slightly lower than the 1.7 μ_B/Co value expected by theory. A narrow magnetic hysteresis loop with a coercive field of 100 Oe at low temperature suggests that Co₃PdN might be useful in electronic applications requiring fast switching of the magnetization vector. While prior prediction of Co₃PdN showed a gapped electronic band structure for each spin channel, we show that this was due to incomplete sampling of Brillouin zone paths and that band crossings exist along R-X|M and X|M-R paths. The metallic nature of Co₃PdN is further confirmed by temperature-dependent transport measurements, which also show a considerable anomalous Hall effect. Altogether, this work represents an appreciable step toward understanding the synthesis, structure, stability, and properties of a new magnetic material.