Preparation of Rocksalt‐Type Semiconductor Ca ₂ TaN ₃ via Hot Isostatic Pressing

The rocksalt‐type double nitride Ca 2 TaN 3 was synthesized via hot isostatic pressing (HIP) at 1400°C and 150 MPa static dinitrogen pressure from Ca 3 N 2 and Ta 3 N 5 . The bright yellow microcrystalline powder crystallizes in the cubic space group with a lattice parameter of a = 4.7473(1) Å. Structure solution by Rietveld refinement reveals that Ca and Ta statistically share a common crystallographic position. Magnetization measurements confirm a diamagnetic compound with tantalum in the oxidation state +V, while UV–Vis spectroscopy reveals a direct bandgap of E gap = 2.46 eV responsible for the yellow body color. Temperature‐dependent X‐ray diffraction demonstrates excellent thermal stability up to 1000°C with a linear thermal expansion coefficient of α a = 9.95(7) × 10 −6 K −1 . This work demonstrates the potential of HIP for the synthesis of alkaline earth transition metal nitrides.