Manganese doped perovskites are promising materials for non-magnetic data storage. Systems with low doping concentration, such as Mn:YAlO3 are high-quality optical crystals, demonstrating significant photorefractive effect. Optically and electrically induced quasi-permanent change in low-field conductivity was observed in the materials with high concentration of manganese such as single crystals and films of LaGa1−xMnxO3 (x= 0.1–1). These memory effects can last for a long time at room temperature and can be easily erased by heating up to 230 C. We explain our experimental results by photoinduced or thermoinduced local phase transition with the oxidation of Mn ions.

We have grown Mn:LaGaO3 crystals (Mn=0.5%, 2%, 10%, and 50%) and studied their properties with the methods of optical and EPR spectroscopy. We have found Mn2+, Mn4+, and Mn5+ ions in low doped crystals (Mn=0.5% and 2%) and Mn3+ ions in crystals with higher Mn concentrations (10% and 50%). The formation of Mn3+ valence state in Mn:LaGaO3 is discussed.

A comparative study of the Czochralski crystal growth of Ca and Sr fluoro-phosphate, Ca and Sr fluoro- and chloro-vanadate is reported. Sr fluoro-phosphate and fluoro-vanadate demonstrate the best overall properties and crystal quality. Codoping of the fluoro-apatite crystals with Si4+ or Ge4+ ions increases the neodymium distribution coefficient but somewhat deteriorate the Nd3+ emission.