Observation of structural phase transition in Nd0.5Sr0.5MnO3 from high real-space-resolution X-ray diffraction

The real-space total scattering atomic Pair Distribution Function (PDF) method has been used to study the effect of temperature (T) on the structural features of the manganite . The powder X-ray diffraction data were collected as a function of T ranging from 92 to 300 K. The PDF data were analyzed at a value of and a room temperature model was used for the refinement of the data at two different refinement ranges (r-ranges): 1.7-10 and 1.7-30 for all the temperatures. Good agreements between the model and the PDF data were obtained with good agreement factor () values and a possible evidence for a structural phase transition (mainly from an orthorhombic Imma to a monoclinic phase) was observed at T = 145 K through the variation of the lattice parameters a, b, and c, and of as T decreases.