A synthetic iron phosphate mineral, spheniscidite, [NH4]+[Fe2(OH)(H2O)(PO4)2]-H2O, exhibiting reversible dehydration

Spheniscidite, a synthetic iron phosphate mineral has been synthesized by hydrothermal methods. The material is isotypic with another iron phosphate mineral, leucophosphite. Spheniscidite crystallizes in the monoclinic spacegroup P2(1)/n. (a = 9.845(1), b = 9.771(3), c = 9.897(1), beta = 102.9 degrees, V = 928.5(1), Z = 4, M = 372.2, d(calc) = 2.02 g cm(-3) and R = 0.02). The structure consists of a network of FeO6, octahedra vertex-linked with PO4 tetrahedra forming 8-membered one-dimensional channels in which the NH4+ ions and H2O molecules are located. The material exhibits reversible dehydration and good adsorption behaviour. Magnetic susceptibility measurements indicate that the solid orders antiferromagnetically.