PEMBUATAN PADUAN INTERMETALIK Mg2Si DENGAN DOPING BISMUTH SEBAGAI MATERIAL TERMOELEKTRIK

Synthesis of Bismuth Doped Mg2Si Intermetallic Alloy as a Thermoelectric Material

Abstract

Increasing efficiency in gasoline fuel consumption in motorized vehicles is currently continuing. One way this is done is by making use of the energy that is lost during the combustion of a motorcycle engine. About half of the energy produced during burning will be lost due to heat energy and exhaust gases. This waste heat can be utilized by converting it into another form of energy. Thermoelectric materials are those that can convert heat energy into electricity directly. Thus, in this work, we synthesized the bismuth-doped Mg₂Si thermoelectric material using a solid-state reaction method using a powder in a sealed tube technique. The initial step in the production process involves measuring the raw materials bismuth, silicon, and magnesium using the Mg₂Si_1-xBi_x formula (x = 0.00, 0.025, and 0.045). The raw material powder is grinded in a shaker mill before being sealed in a stainless steel tube. The powder is sealed in a tube and heated to 800 °C for 6 hours. According to XRD test results, the Mg₂Si phase and Si and MgO phases have formed. The lattice constant of the cubic Mg₂Si phase was found at ~0.636 nm. A SEM investigations of surface morphology suggest that bi-doping on Si sites influences grain size refinement. Therefore, it can be concluded that the Mg₂Si intermetallic alloy production process was successfully completed.