Electrical conductivity variation of (Bi2Te3)0.25(Sb2Te3)0.75 crystal grown using the zone melting method

Experiments and numerical results are presented to demonstrate the adverse effects of a zone melting method in (Bi2Te3)(0.25)(Sb2Te3)(0.75) thermoelectric crystallization, on mass transport. The zone melting method shows a considerable effect from the deflection of the solid liquid interface, and the Bi2Te3 stoichiometry changes significantly. Electrical conductivity measurements of the crystallized ingot were carried out at stepped intervals of length (each step is 7 mm). A considerable gradient was observed in the readings from the tip to the end of the ingot. To understand this variation taking into account all empirical aspects of crystal growth, we conducted a numerical study because it gives vast information on the crystal growth process. Simulating the crystallization process and characterization of the ingot reveals a variation in the measured values of the thermoelectric parameters, which was attributed to the deviation of Bi2Te3 concentration along the ingot.