Flux growth and liquid-phase epitaxy of Mn6+ -doped molybdates and tungstates

We performed a systematic investigation of Mn⁶⁺ in (Ca/Sr/Ba)(Mo/W)O₄ compounds which can be divided into three parts. Crystal-growth experiments in order to estimate the best conditions for liquid-phase epitaxy (LPE) of thin films doped with Mn⁶⁺, whose spectroscopic properties are then studied. Since Mn⁶⁺ tends to be reduced to Mn⁵⁺ at temperatures T>600°C, we used NaCl-KCl-CsCl as a solvent for the flux and LPE experiments. Due to the low solidification temperature of the solvent (480°C), the maximum growth temperature could be kept below 600°C. The dependencies of the crystal dimensions versus solute concentration for all six (Ca/Sr/Ba)(Mo/W)O₄ compounds were constructed from the results of the flux experiments.