Structural, Magnetic, and Ion-Exchange Properties of RbMnHP(3)O(10).
The crystal structure, magnetic properties, and ion-exchange behavior of RbMnHP(3)O(10) have been determined. The crystal structure (a = 12.1866(3) Å, b = 8.3586(2) Å, c = 9.0763(3) Å, beta = 109.067(1) degrees, space group C2/c), determined from X-ray powder diffraction, is of NH(4)FeHP(3)O(10) type, consisting of hydrogen triphosphate anions linking Jahn-Teller distorted Mn(III)O(6) octahedra around Rb(+) cations. Magnetic susceptibility measurements and low-temperature neutron powder diffraction show that RbMnHP(3)O(10) behaves as a Curie-Weiss paramagnet at high temperatures and orders antiferromagnetically below a Néel temperature of 10 K. The magnetic structure is commensurate with the nuclear cell, and the collinear antiferromagnetic structure has magnetic symmetry group P(C)()2/c' with spins of 3.82(6) &mgr;(B) lying in the ac plane. Exchange of H(+) for Li(+) has not proved possible without a breakdown of the RbMnHP(3)O(10) framework due to strong symmetric hydrogen bonding between triphosphate anions.
Wright
A. J.
AJ
Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
Attfield
J. P.
JP