Perovskite-type solid solution SrMo_1-xW_x(O, N)₃ oxynitrides: Synthesis, structure, and magnetic properties

Phase-pure scheelite-type solid solution SrMo_1-xW_xO₄ oxides (x = 0.05, 0.15, 0.25, 0.4, 0.5, 0.6, 0.75, 0.85, 0.95) were synthesized by solvothermal methods and subsequently thermally treated in ammonia atmosphere at temperatures between 700 and 900 °C. As revealed by X-ray diffraction (XRD) and neutron diffraction as well as elemental analysis data, SrMo_1-xW_xO₄ convert into their corresponding solid solution perovskite-type oxynitrides SrMo_1-xW_x(O, N)₃ only for x ≤ 0.25 and x ≥ 0.6; whereas for 0.25 ≤ x ≤ 0.6 the formation of Sr₃WO₆ with double perovskite structure and of other binary oxides and nitrides was observed. The solid solution oxynitrides were investigated concerning their magnetic properties. Thus, the magnetic susceptibility of the SrMo_1-xW_x(O, N)₃ oxynitride samples was measured by Superconducting Quantum Interference Device (SQUID). The influence of different parameters (such as phase composition, ratio between Mo and W or nitrogen content) on the magnetic behavior in the solid solution oxynitrides is briefly discussed.