GROWTH AND CHARACTERIZATION OF (Y,Nd)Al3(BO3)4 AND (Y,Gd)Al3(BO3)4 CRYSTALS. Leonyuk, N.I.; Koporulina, E.V.; Belokoneva, E.L.; Titov, Yu.V., Moscow State University, Russia
The crystals of solid solutions based on the YAl3(BO3)4, NdAl3(BO3)4 and GdAl3(BO3)4 borates with huntite type structure (R32 space group) are excellent materials for laser and acoustic devices [1,2]. However, the NdAl- and GdAl-borates and their solid solutions tend to the phase transitions from huntite type structure into monoclinic modifications [3]. The purpose of the present work was to establishe a correlation between the growth conditions, contens of crystals and phase transitions in (Y,Nd)Al3(BO3)4 and (Y,Gd)Al3(BO3)4 solid solutions.
These crystals were grown from a K2Mo3O10- containing fluxed melts in temperature range 1060-990deg.C (spontaneous crystallization) or 1050-1010deg.C (TSCG).
The distribution coefficient (K=Cs/Cl) was estimated to be 0.3-0.8 for NYAB and about 1 for GYAB crystals. In the case of NYAB it increases with an increase in crystallization temperature and a decrease in the crystal growth rate.
The temperature and concentration ranges of the phase transitions were determined for these crystals by X-ray technique, microprobe analysis, optical and electron microscopy.
Referenses
1. L.M.Dorozhkin at all. Pis`ma v ZhETF, Vol.7, pp.1297-1299 (1981) (in Russian).
2. L.I.Leonyuk at all. Acoustoelectronics-89, Abstr, Varna, Vol.2, pp.459-461 (1989).
3. E.L.Belokoneva at all. Kristallographia, Vol.33, pp.1287-1288 (1988) (in Russian)