SYNTHESIS OF THERMOELECTRIC MATERIAL OF CA3CO4O9 BY MEANS OF SONOCHEMISTRY AND SOLID-STATE REACTION METHOD

• Main Author: Al Muflih, Miqdad
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/52293
• Institution: Institut Teknologi Bandung

Thermoelectric materials can be used to convert thermal energy into electrical one. The thermoelectric properties are mainly based on the Seebeck effect. The quality of the thermoelectric material is determined by the figure-of-merit (ZT) value. High thermal stability and low toxicity of material are required for good thermoelectric material. The oxide compound of Ca3Co4O9 is a promising thermoelectric material with ZT values are between 0.1-0.3 in its polycrystalline solid form. The study on the effect of the synthesis method on the thermoelectric properties of Ca3Co4O9 has been carried out. Ca3Co4O9 is consist of two different layers of CoO2 layer and Ca2CoO3 one. These two layers affect the electrical and thermal conductivity of the Ca3Co4O9 material. Studies of various synthesis methods of Ca3Co4O9 show that the crystal synthesis method affects the phonon scattering and the charge scattering between polycrystalline grains, then, will affect thermal conductivity and electrical conductivity. The crystals shape and size can be controlled through the Bottom-Up approach. The sonochemistry method, in principle, is one of the synthesis methods that using the bottom- up approach. As a comparison, the synthesis using the solid phase method was also carried out. The synthesized products were characterized by the X-ray diffraction (XRD) method. Sonochemistry method produced a multiphase sample, which consist of Ca3Co4O99 phase and Ca2Co2O5, while the solid phase method synthesis produced a pure Ca3Co4O9 phase.