Crystal formation of Cu-Mn-containing oxides and oxyborates in bismuth-boron fluxes diluted by MoO3 and Na2CO3

The high-temperature crystallizing phases of fluxes (molten solutions) based on Bi₂O₃:MoO₃ = 1:3 and diluted by Na₂CO₃ and B₂O₃ (under varying of Na₂CO₃:B₂O₃), and by CuO and Mn₂O₃ (0 ≤ Mn₂O₃:CuO ≤ 5) are studied. The conditions of the stable crystallization of Mn²⁺_1−xCu_xMoO₄, Mn₂³⁺O₃, Mn²⁺Mn₂³⁺O₄, Mn²⁺_1−xCu_xMn³⁺BO₄ and Mn²⁺_2−xCu_xMn³⁺BO₅ have been found. The influence of MoO₃ and Na₂CO₃ to the crystallization processes of Mn²⁺- and Mn³⁺-containing Mn²⁺_1−xCu_xMoO₄ and Mn²⁺Mn₂³⁺O₄ and Mn₂³⁺O₃ are clarified. The occurrence of the chemical bonds of these types at the crystallization of Mn-heterovalent Mn²⁺_1−xCu_xMn³⁺BO₄ and Mn²⁺_2−xCu_xMn³⁺BO₅ oxyborates is studied. Single crystal growth techniques of these oxyborates are suggested. The results of the structural and magnetic characterization of some discussed compounds are presented.