Visualization of the antiferromagnetic insulator-ferromagnetic metal phase transition in manganite Nd0.5Sr0.5MnO3

It is found that the first-order phase transition from a nonmetallic antiferromagnetic (AFM) state to a metallic ferromagnetic (FM) state in manganite Nd0.5Sr0.5MnO3 is accompanied by a significant change in the reflectivity of the visible light. This effect is used for visualizing the AFM-FM phase transition in Nd0.5Sr0.5MnO3. The coexistence of AFM and FM phases was observed visually during spontaneous and field-induced AFM-FM transitions. In both cases, the transition occurs through nucleation and expansion of domains of the phase that is favorable from the energy point of view. However, the periodic domain structure of the intermediate magnetic state was not formed during the phase transition. A striped domain structure was formed in the AFM state while the FM phase had a uniform structure. (C) 1999 American Institute of Physics.