Study of the phase transition and charge ordering in single-crystalline Nd_(1/2)Sr_(1/2)MnO_3 using x-ray scattering

摘要

We report a sequent phase transition using high-resolution synchrotron x-ray scattering in a single crystal Nd_(1/2)Sr_(1/2)MnO_3. By measuring the peak profile of Bragg reflections, upon cooling, we observed an increase in the width of the Bragg reflections around the Curie temperature (252 K) corresponding to the transition from a paramagnetic to a ferromagnetic state. Below approximately 200 K, dramatic changes in the width and integrated intensity were observed. Changes continued until the formation of charge ordering with q=(1/2,0,0) at T_(CO)=152 K. This charge ordering was observed to be the first order transition with a large hysteresis width of 10 K. This sequent transition is understood by the formation of different magnetic domains at different temperature ranges as that observed by neutron powder diffraction.