Crystal structure evolution of Sm0.6Sr0.4MnO3 in the temperature range 1.5-300 K

Neutron powder diffraction experiments on (Sm0.6Sr0.4MnO3)-Sm-154 in the temperature range from 1.5 to 300 K have been performed using the high-resolution G4.2 (LLB, France) diffractometer. The material undergoes an insulator-metal transition at T similar to 120 K and exibits the giant magnetoresistance effect. The Jahn-Teller transition temperature is found to be close to 180 K. The temperature dependence of microstrain parameters related to anisotropic peak broadening is obtained. Magnetic scattering detected for T < 130 K can be formally attributed to the canted ferromagnetic state. The consequences of our experimental results are discussed in the context of current ideas about structure and magnetotransport properties of manganites. (C) 2000 Elsevier Science B.V. All rights reserved.