Evolution of structural phase coexistence in a half doped manganite Pr0.5Sr0.5MnO3: An evidence for magneto-structural coupling

Temperature dependent x-ray diffraction measurements have been performed to understand the implications of magnetic phase coexistence on crystallographic structure in a half-doped manganite Pr0.5Sr0.5MnO3. The compound shows a structural phase transition from high-temperature tetragonal-I4/mcm to low-temperature orthorhombic-Fmmm symmetry around the ferromagnetic to antiferromagnetic transition. Rietveld analysis shows the coexistence of these two structures emerges at high temperature within the ferromagnetic state, and persists down to lowest temperature. Below around 40 K, however, this structural evolution stops, and a significant fraction (∼22%)(∼22%) of untransformed high-temperature phase remains. This agrees with earlier magnetization study, thus establishing its magneto-structural coupling.

► Temperature dependent x-ray diffraction measurements are done on Pr0.5Sr0.5MnO3.
► With temperature, there is a structural phase transition from I4/mcm to Fmmm symmetry.
► These two structural phases coexist in wide temperature range.
► At low temperature, about 22% untransformed high temperature phase is present.
► This agrees with magnetic data, hence establishing its magneto-structural coupling.