Infield X-ray diffraction studies of field and temperature driven structural phase transition in Nd0.49Sr0.51MnO3+delta

Comprehensive X-ray diffraction (XRD) studies have been performed at different temperature (T) (4.2-300 K) and magnetic field (H) (0-8 T) to understand the evolution of crystal structure of Nd0.49Sr0.51MnO3+delta (NSMO) under non ambient conditions. The T dependent XRD results show the abrupt change in the lattice parameters without any change in lattice symmetry at similar to 200 K, which is associated with the first order structural phase transition from ferromagnetic to antiferromagnetic phase. This phase transition is strongly H dependent and shifted to lower temperature (similar to 150 K) on the application of 8 T field with phase coexistence (high temperature phase similar to 18%), even down to 4.2 K. Isothermal XRD results at 150 K under different H clearly illustrate the H induced first order structural phase transition. The critical H at which this phase transformation starts is similar to 1 T, with rapid growth above 4 T with hysteretic nature during increasing and decreasing H. These results are supported with the resistivity and magnetoresistance results and affirm the strong spin-lattice coupling in NSMO. Our detail studies reveal the structural correlations to the observed colossal magnetoresistance and magnetocaloric effect in this material. (C) 2017 Elsevier B.V. All rights reserved.