Electrochemical crystal growth and properties in Ln₂O ₃-MnO-CoO (Ln=La, Ho) system

We have developed a known approach of electrochemical deposition to grow successfully neutron sized single crystals of pure and mixed compounds in the Ln₂O₃-MnO-CoO system. Reported in detail, it is a growth technique with a seed of LnAO_3+x (Ln=La, Ho; A=Co, Mn) single crystals up to 2 cm³ in volume using the 2.2Cs ₂MoO₄-MoO₃ mixtures as solvent. The best crystals were grown in the temperature range 1050-1100 °C to reveal FWHM ∼0.1° of the rocking curves. A primary crystallization temperature range for LaCo_1-xMn_xO₃ ternary oxides was found to be 830-1170 °C. But, quasi-equilibrium growth was seen only for the temperature interval 1000-1050 °C. In turn, much more stable growth and wide primary crystallization field were registered for single crystals of HoCo_1-xMn_xO₃ solid solution. The grown crystals accept mostly a cubic-like shape. However, weekly developed (1 1 1) type faces could be recognized in some cases. Here, we also report on studies of crystal field excitations and present the data of magnetic susceptibility of the electrochemically grown crystals.