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.