Single crystal growth of tantalite ((Fe,Mn)(Ta,Nb)2O6) solid solutions

In the system of MnTa2O6-FeTa2O6, Mn2+ was substituted up to about 80 at% for Fe2+ in trirutile-type FeTa2O6, and Fe2+ was substituted up to 13 at% for Mn2+ in MnTa2O6. In the MnNb2O6-MnTa2O6 system, all solid solutions had the columbite-typ structure. Single crystals of tantalite solid solutions having the composition of FexMn1−xTa2O6 (0.00 ≦ x ≦1.00) and Mn(TayNb1-y)2O6 (0.00 ≦ y ≦ 1.00) were grown by the floating zone method using an infrared heating furnace unde controlled atmosphere of oxygen pressure. Trirutile-type single crystals of FexMn1-xTa2O6 with 0.40 ≦ x ≦ 1.00 and col type single crystals of Mn(TayNb1-y)2O6 with 0.00 ≦ y ≦ 0.50 were obtained. The crystals were 5 mm in diameter by about length, and were crack-free, metallic lustrous and black.