Magnetic Properties of Manganese Pyrophosphate and Copper Pyrophosphate

Abstract

<p> The magnetic structures of antiferromagnetic manganese pyrophosphate and copper pyrophosphate have been determined by single crystal neutron diffraction techniques. More detailed features of the magnetic structure have been determined by nuclear magnetic resonance (NMR). A discrepancy between previous NMR measurements on Mn2P2o7 and the single crystal neutron measurements was resolved by postulating a low temperature crystallographic phase transition. Information about the dependence of the transferred hyperfine interaction upon the separation of the relevant ions is obtained for Cu2P2o7 from the NMR data and from previously determined deviations from a higher symmetry phase. The origin of the magnetic anisotropy energy in Cu2P2o7 is discussed. </p>