Observation of twin-like composition modulation and phase separation with long-range order induced by oxygen deficiency in single crystal manganites

Single crystal La 2/3 Sr 1/3 MnO 3− δ manganite with an unusual structure was obtained by the optical-floating method with controlled growth in a flowing argon atmosphere. A modulated twin-like structure with phase separation characteristics in the long-range order is found. The energy-dispersive X-ray spectroscopy measurement reveals that there is a strong chemical fluctuation for different stripes, i.e. resulting from the nonstoichiometry due to oxygen deficiency. After annealing, the twin-like stripe phase disappears and the single crystal shows excellent properties. These results may be of great significance for controlled growth of oxide electronics materials with artificial superstructure-like technique.