Synthesis and Single Crystal Growth by Floating Zone Technique of FeCr2O4 Multiferroic Spinel: Its Structure, Composition, and Magnetic Properties

Abstract

We present the new synthesis root of spinel-structure FeCr2O4 and its single crystal growth by the optical floating zone method, ensuring its single phase and near-ideal composition. The advantage of the proposed synthesis method is the creation of the reducing atmosphere in the oven needed for preserving the Fe2+ oxidation state via decomposition of the iron (II) oxalate FeC2O4 used as one of the initial components. The occurrence of the Fe3+ ions in the obtained polycrystalline samples as well as grown single crystals was carefully monitored by means of Mössbauer spectroscopy. Magnetic susceptibility and heat capacity temperature dependences reveal a sequence of the structural (138 K) and magnetic (at 65 K and 38 K) phase transition characteristics for the FeCr2O4 compound.