Microthermocouples of a Glass-Insulated Bifilar Microwire Based on Bi₂Te₃

Abstract

The paper presents the results of studies related to the technology for obtaining glass-insulated bifilar microwires (BMWs) of a thermoelectric material based on Bi₂Te₃ with one wire exhibiting the n-type and the other p-type conduction as well as the study of their mechanical properties by the strain method and the microscopic analysis of the morphology of structural defects with a view to preparing microthermocouples on their basis.

Preliminary studies showed that BMWs are more flexible than single microwires of the same material. The rupture strength of BMWs per unit cross section of a sample (together with the glass) ranges within 18-6 kg/mm² with respect to diameters of 90-120 μm.

Microthermocouples with a signal value on the order of 2-12 mV in a temperature range of 23-50°C have been developed. The preparation of thermoelectric microthermocouples of BMWs significantly reduces the number of process operations in the course of their production and considerably increases their resistance to impacts and vibrations. Microthermocouples based on glass-insulated BMWs have smaller sizes and weight; they can be used for measuring temperatures in chemically aggressive media.