Melt growth of (Tb,Lu)(3)Al5O12 mixed garnet fiber crystals

The substitution phenomenon in the (Tb,Lu)(3)Al5O12 mixed garnet crystals h ave been studied by solidification of corresponding stoichiometric melts us ing micro-pulling-down apparatus. By substitution of Tb3+ with Lu3+, th, te ndency of TbAlO3 perovskite phase formation in undoped Tb3Al5O12 decreases. Although growth of mixed crystals in general does not allow uniform distri bution of constituents in the resulting material, the invariant point was f ound to exist in the system studied in the vicinity of Tb2.2Lu0.8Al5O12 com position. Thus, the uniform single-crystal fibers of the above materials up to 500 mm in length and about 1.3 mm in diameter were produced at a pullin g-down rate of 1.2 mm/min. (C) 2000 Elsevier Science B.V. All rights reserv ed.