Development of Negative Thermal Expansion Fine Particles

Because of growing demands for thermal expansion control in a local region, typically inner components electronic devices, there is currently great deal interest negative (NTE) fine particles. The spray-drying method without grinding produced micrometer-scale particles pyrovanadate Cu1.8Zn0.2V2O7 showing large coefficient linear αL ~ –14 ppm/K equivalent to that the bulk body. solid-solution system Cu1.8Zn0.2V2–xPxO7 maintains NTE functionality wide x compositional range. Phosphorus substitution contributes cost reduction and improvement electrical insulation. Control structural phase transition phosphate analog Zn2P2O7 by substituting Mg Zn realized huge exceeding –60 over temperature range including room temperature. small are obtainable even with conventional solid-phase reaction, 1 μm level were obtained successfully using pulverization degrading function. It has high practicality because it composed only inexpensive environmentally friendly elements such as Zn, Mg, P. These expected support progress engineering.