Vanadium Octacyanoniobate-Based Magnet with a Curie Temperature of 138 K

In this work, we prepared a three-dimensional vanadium octacyanoniobate-based magnet, K0.10VII0.54VIII1.24[NbIV(CN)8]·(SO4)0.45·6.8H2O. This compound exhibits ferrimagnetism with a Curie temperature of 138 K, in which the sublattice magnetizations of VII (S = 3/2) and VIII (S = 1) are antiparallelly ordered to that of NbIV (S = 1/2). The estimated superexchange interaction constants of VII−NbIV and VIII−NbIV are −51 and −25 cm−1, respectively.