WEAK FERROMAGNETIC BEHAVIOR OF THE MANGANESE ALKYLPHOSPHONATE HYDRATES MNCNH2N+1PO3.H2O, N=1-4

Alkylphosphonates MnCnH2n+1PO3 · H2O, n = 1-4, were prepared from aqueous solution and studied using bulk magnetic techniques. Orthorhombic unit cell parameters have been determined from X-ray powder data. The compounds form a homologous series, apparently analogous to the inorganic phosphates MIMII PO4 · H2O, consisting of distorted MO6 octahedra cross-linked into sheets by phosphohate oxygens, the sheets being separated by alkyl chains. All four compounds are canted antiferromagnets, with ordering temperatures in the range 14.8-15.1 K. The magnitude of the spin canting varies significantly with the length of the alkyl chain; there is also an apparent alternation in TN with odd and even chain lengths. © 1993 Academic Press, Inc.