Effects of Synthesis Conditions on Formation and Electrical Resistivity of Composite Powders Containing Layered Tin Compound

Abstract

The effect of synthesis temperature, pH condition, poly (vinyl alcohol) (PVA) addition and post synthesis treatment by H₂O₂ on the crystal phase and their electrical resistivity of the powder prepared through the hydrolysis reaction of tin chloride was investigated. A powder that has strong X-ray diffraction (XRD) pattern which corresponds to periodic layered structure and weak Sn₃O₂(OH)₂ signals were obtained when the synthesis condition was controlled to 90℃ and pH=2.4～4.2 with PVA addition. The XRD peak intensity of the layered structure drastically reduced when PVA was not added or the synthesis temperature was below 50℃. It was also found that the Sn₃O₂(OH)₂ phase could be transferred to SnO_2-x when the additive content of H₂O₂ was nearly equivalent to Sn content. Among samples prepared under various pH values and temperatures, it was confirmed that the composite samples with stronger XRD diffraction signals from periodic layered structure possesses lower resistivity.