Crystal growth and characterization of Marokite CaMn2O4+δ

Centimeter-sized single crystals of CaMn2O4+delta, commonly known as Marokite, were grown using the floating-zone method. The growth conditions are reported along with a discussion of a simple method for polycrystalline rod preparation, which differs from the typical cold isostatic pressure procedure. Crystal characterization was determined by powder X-ray diffraction, back-reflection Laue diffraction, iodometric titration, energy-dispersive X-ray spectrometry, and vibrating sample magnetometry. Polycrystalline rods, composed of stoichiometric Marokite, were found to produce crystals with CaMnO3 as a secondary impurity phase as revealed by magnetic measurements and powder diffraction. Crystals grown from polycrystalline rods with excess manganese oxide produced single crystals of high quality without impurity phases. (C) 2008 Elsevier B.V. All rights reserved.