Structure, magnetic properties and magnetic phase diagram of a layered, bimetallic, cyanide-bridged Cr-III-Ni-II metamagnet

The reaction of hexacyanochromate(III) with Ni(tmc)(2+) (tmc = tetramethylc yclam) leads to the formation of the layered compound [Ni(tmc)](3)[Cr(CN)(6 )](2). 18H(2)O displaying a corrugated sheet structure. Within each layer, the Ni(tmc) units are surrounded by two Cr(CN)(6) complexes in a trans fash ion while the Cr(CN)(6) units are Linked to three Ni(tmc) molecules in faci al positions. The magnetic studies show ferromagnetic interaction for a Ni- II((d)8,t(2g)(6)e(g)(2))-CN-Cr-III(d(3),t(2g)(3)) system within the layers. Below a critical temperature (T-N = 14 K), a bulk antiferromagnetic order is observed due to a small interlayer antiferromagnetic interaction. An ant iferromagnetic --> ferromagnetic phase transition occurs for an applied fie ld He of 1200 Oe expressing the metamagnetic behavior of the compound. The phase diagram of the compound was constructed and the antiferromagnetic int erlayer magnetic energy was estimated to be equal to 0.1 cm(-1).