CRYSTAL-GROWTH AND THERMODYNAMICS OF N-TYPE BI2(TE1-XSEX)3 SINGLE-CRYSTAL SOLID-SOLUTIONS (X-LESS-THAN-OR-EQUAL-TO-0905)

Bi2(Te1-xSex)3 single crystal solid solutions with x = 0.025 and x = 0.05 have been grown using the travelling heater method. The first step of this work was the study of the Bi-Te-Se ternary phase diagram on the Bi2Te3-rich side and with excess tellurium. The isoconcentration lines for these two compositions have been determined for temperatures ranging from 550-degrees-C to their melting points. The knowledge of this phase diagram allows us to grow homogeneous ingots of high crystalline quality. The solidus line on the Te-rich side for these compositions has been determined by Hall effect measurements. This study shows that it is possible to grow thermodynamically well-defined single crystals in a reproducible way.