Synthesis, Crystal Structures, and Magnetic Properties of Layered Vanadium Oxides: A2V4O9 (A = Rb, Cs)

Single crystals of Cs2V4O9 were grown in a CsBr flux and two polytypes of Cs2V4O9 have been identified by both single-crystal and powder X-ray diffraction. Phase 1, α-Cs2V4O9, crystallizes in the tetragonal system, space group P42/m, with a = 5.727(1) Å, c = 15.052(3) Å, Z = 2, and its structure has been refined based on F2 to R1 = 0.0809, wR2 = 0.1015 using all 1450 independent reflections from a nearly perfectly twinned crystal. Phase 2, …