Cold neutron study on the diffuse scattering and phonon excitations in the relaxor Pb(Mg1/3Nb2/3)O3 -: art. no. 184105

Cold neutron scattering experiments have been performed to explore the energy, temperature, and wave-vector dependence of the diffuse scattering and the transverse acoustic (TA) phonons in the relaxor Pb(Mg1/3Nb2/3)O-3. We have observed a weak diffuse scattering cross section above the Burns temperature T(d)similar to600 K. This cross section, which is most likely caused by chemical short-range order, persists down to 100 K, and coexists with the much stronger diffuse scattering that is attributed to the polar nanoregions. A systematic study of the TA phonon around (1, 1, 0) has also been carried out. The phonon is well defined for small wave-vectors q, but broadens markedly around q=(0.1,-0.1,0).