Aspects of the structure and dynamics of the CMR material Nd0.5Pb0.5MnO3

Single-crystal neutron diffraction measurements on the colossal magnetoresi stance (CMR) material Nd-0.5 Pb-0.5 MnO3 show diffuse scattering at +/- (2/ 3, 0, 0) from strong Bragg peaks, but with no significant temperature depen dence. Inelastic scattering measurements show that this is elastic in origi n and hence probably due to some preferential ordering of Nd and Pb. The di spersion of some acoustic phonon branches has been measured and also shows no significant temperature dependence, suggesting that optical phonons are responsible for the electron-phonon coupling and the CMR behaviour. (C) 200 0 Elsevier Science B.V. All rights reserved.