LAUSR

Abstract Zr 2 W 2 P 2 O 15 with larger-negative-thermal-expansion-coefficient (NTEC, −4.01×10 −6  K −1 , 143–673 K) is developed by controlling reaction process to avoid the intermediate phase of Zr 2 WP 2 O 12 , whose smaller NTEC limits its application. From 1473 K to1573 K, Zr 2 WP 2 O 12 forms easily but the reaction between Zr 2 WP 2 O 12 and WO 3 to generate Zr 2 W 2 P 2 O 15 is difficult even followed by heating up to 1673 K. However, putting raw materials of ZrO 2 , WO 3 and NH 4 H 2 PO 4 into a pipe furnace at sintering temperature 1673 K directly, the Zr 2 W 2 P 2 O 15 is formed avoiding the intermediate phase of Zr 2 WP 2 O 12 .