Growth of Sr2/3Ln1/3FeO3 (Ln=La, Pr, and Nd) single crystals by the floating zone technique

We report the growth of Sr2/3Ln1/3FeO3 single crystals (Ln=La, Pr, and Nd) by means of a floating zone melting method under a moderately high oxygen pressure (2–3 bar). We find that the boules are free of impurities or secondary phases but single crystals are only obtained using low growing rates. The La-based compounds crystallize in a rhombohedral structure, whereas crystals with Pr and Nd are orthorhombic. The as-grown crystals, which are oxygen deficient, exhibit smeared magnetic and resistive transitions upon cooling. The annealing at high oxygen pressure restores oxygen stoichiometry. The oxidized crystals show sharp resistive and magnetic transitions.