NEW TUNGSTEN PYROPHOSPHATE WITH CUBIC ZIRCONIUM PYROPHOSPHATE-TYPE STRUCTURE

Tungsten pyrophosphate, WP2O7, was prepared by reacting mixtures of (N H4)2HPO4, WO3 and W at 900-degrees-C in an evacuated quartz tube. Powd er X-ray diffraction study shows the compound to be isostructural with cubic zirconium pyrophosphate, ZrP2O7, with a = 7.947(1) angstrom. Th e electrical resistivity of the compound at room temperature is in the Mega-Ohm region indicating insulating behavior. The magnetization stu dy made on a pelletized sample shows a paramagnetic behavior similar t o MoP2O7. The effective magnetic moment calculated in the temperature range 100-300 K is 2.4 BM.