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 t he Bi2Te3-rich side and with excess tellurium. The isoconcentration li nes for these two compositions have been determined for temperatures r anging from 550-degrees-C to their melting points. The knowledge of th is phase diagram allows us to grow homogeneous ingots of high crystall ine quality. The solidus line on the Te-rich side for these compositio ns has been determined by Hall effect measurements. This study shows t hat it is possible to grow thermodynamically well-defined single cryst als in a reproducible way.