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 TC = 560 +- 5 K. The saturation magnetization of 1.2 ..mu..B/Co found in the experiment is slightly lower than the 1.7 ..mu..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.