SEMICONDUCTOR SENSOR FOR DETECTING VOLUME CHANGES AT LOW TEMPERATURES

The article discusses the technological aspects of the production of stoichiometric alloys with the addition of Pb with high thermoelectric properties and their use in the film version as sensors for volume changes at low temperatures. Keyword: adhesion, deformation, defect, alloy, thermoelectricity, strain sensitivity. Introduction. To study the strength of structures, it is necessary to measure local deformations, forces, pressure, temperatures, displacement, control the moments of occurrence of defects and the speed of their development. At the same time, special requirements are imposed on measuring devices: ensuring high metrological characteristics of each individual measurement, provided that the measurements are massive. Mass measurements are understood to mean measurements during which a correspondence is established between the measured value and the reference value for a plurality of homogeneous sensors of primary transducers. Material and Methods: Upon receipt of semiconductor materials, the thermoelectric properties of alloys depend not only on the composition, but also on the purity of the starting components. Therefore, materials obtained from various batches of raw materials often differ in their thermoelectric properties. In practice, it is convenient to determine the characteristics of the feedstock by the thermoelectric properties of the base (undoped material) fused from this feedstock [1]. As is known, when Bi2Te3 and Bi2Se3 are alloyed the thermoelectric properties of the alloy change with a change in the batches of the feedstock, since while the properties of the base itself also change. Naturally, when the thermoelectric properties of the base change, the optimal concentration of the dopant, should also be changed. Usually, the optimum concentration of a dopant for a substrate with certain properties is found empirically by conducting a gray melt with a different concentration of dopant. For alloying Bi2Te3 and Bi2Se3, bases with the following thermoelectric properties are selected: electrical conductivity  =200÷600 Ω·sm, thermoelectric coefficient  =240÷200 μV/deg. Discussion: The initial components chosen by us for the preparation of the alloy of the required composition were of the following purity: bismuth GOST 10928-64 brands В400, tellurium ГОСТ9514-60 brands ТА-1, antimony ГОСТ 1069-62 brands С-0 и lead С-00. Based on the works [2], the composition of the solid solution corresponding to 74 mol % was chosen as the basis for the study. Sb2 Te3 and 26 mol % Bi2 Te3. European Journal of Molecular & Clinical Medicine ISSN 2515-8260 Volume 7, Issue 2, 202