GROWTH-CONDITIONS AND SOME PROPERTIES OF TMB4 AND TMALB4 SINGLE-CRYSTALS OBTAINED FROM HIGH-TEMPERATURE ALUMINUM METAL SOLUTION

TmB4 and TmAlB4 single crystals were obtained by the high-temperature aluminium solution method using thulium oxide powder and crystalline boron powder as starting materials. The optimum conditions to obtained relatively large crystals mentioned above were found to include soaking temperature 1500-degrees-C, soaking time 10 h, cooling rate 50-degrees-C.h-1 and the atomic ratios of starting materials: B/Tm=5.5, Al/Tm=119.25 for TmB4; B/Tm=2.0, Al/Tm=119.25 for TmAlB4. In the case of TmB4, Polyhedra single crystals were obtained. The ternary single crystals TmAlB4 were generally obtained in the form of prismatic shape extending in the [001] direction or with well developed (100) faces. The as-grown TmB4 and TmAlB4 single crystals were used for chemical analysis and measurements of unit cell dimensions. Densities, microhardness and electrical resistivity of the as-grown crystals was studied.