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 te mperature range from 1.5 to 300 K have been performed using the high-resolu tion G4.2 (LLB, France) diffractometer. The material undergoes an insulator -metal transition at T similar to 120 K and exibits the giant magnetoresist ance effect. The Jahn-Teller transition temperature is found to be close to 180 K. The temperature dependence of microstrain parameters related to ani sotropic peak broadening is obtained. Magnetic scattering detected for T < 130 K can be formally attributed to the canted ferromagnetic state. The con sequences of our experimental results are discussed in the context of curre nt ideas about structure and magnetotransport properties of manganites. (C) 2000 Elsevier Science B.V. All rights reserved.