(198b) Effect of Graphene Oxide on Formation of Zirconium Tungstate Nanoparticles

Development of novel inorganic nanofillers is important in the processing of semiconductors. For instance, incorporation of inorganic nanoparticles in polymer composites can alleviate thermal stresses by reducing a difference in the thermal expansion coefficients between polymer and metal or ceramic materials. In particular, zirconium tungstate (ZrW₂O₈) has attractive physical properties for a nanofiller because it has a large isotropic negative thermal expansion coefficient in the temperature range of 0.3 K to 1050 K. Although several methods for synthesis of ZrW₂O₈ particles have recently been reported, most of the proposed protocols provide rod-shaped particles in micrometer range. To achieve desired particle properties, however, control on the size and shape of these particles is required. In this study, we investigate roles of graphene oxide on the formation of ZrW₂O₈ particles. First, we prepare ZrW₂O₇(OH)₂ that is a precursor of ZrW₂O₈ by a hydrothermal method. Next, ZrW₂O₇(OH)₂ is calcinedat 900 K, which transforms ZrW₂O₇(OH)₂ to ZrW₂O₈. We investigate effects of graphene oxide and other reaction parameters on the size and shape of ZrW₂O₈ particles. We expect this study to help control the size and morphology of ZrW₂O₈ particles for semiconductor applications.