Enhancement of the Magnetic Ordering Temperature (and Air Stability) of a Mixed Valent Vanadium Hexacyanochromate(III) Magnet to 99 °C (372 K), Ø. Hatlevik, W. E. Buschmann, J. Zhang, J. L. Manson, and J. S. Miller, Adv. Mater. 11, 914-918 (1999).

The magnetic ordering temperature, T_c, of a vanadium hexacyanochromate(III) magnet has been enhanced to 350 and 372 K. The nominal composition of the 350 ± 1 K magnet is K_0.50V^II/III[Cr^III(CN)₆]0. 95•1.7H₂O while the nominal composition of the 372 ± 1 K magnet is K_0.058V^II/III[Cr^III(CN)₆]0 .79•(SO₄)_0.058•0.93H₂O and both are prepared from the reaction of K₃[Cr^III(CN)₆] and K₂V^II(SO₄)₂•6H_{2< /SUB>O. Previously, V^II0.42V^III0.58[Cr^III(CN)< SUB>6}]_0.86•2.8H₂O prepared from the reaction of K₃[Cr^III(CN)₆] and (NH₄)2V^II(SO₄)₂ was reported to have a T_c of 315 K. The 18% increase in T_c is attributed to the increase in the relative amount of S = 3/2 V^II with respect to S = 1 V^III.