Growth of single crystals of ZrW2O8

The compound, ZrW2O8, exhibits an unusual negative coefficient of thermal e xpansion of approximately -10 ppm/degrees C over ambient temperatures. The incongruent decomposition point-and narrow thermal stability limits of ZrW2 O8 from 1105 to 1257 degrees C severely restrict crystal growth conditions. However, single crystals of ZrW2O8 having masses on the order of a gram we re grown by an unusual layered self-flux technique. Crystals were character ized by X-ray diffraction, inductively coupled plasma emission spectroscopy , dilatometry, and etching behavior. Details of the crystal growth techniqu e and possible growth mechanisms are discussed. (C) 2000 Elsevier Science B .V. All rights reserved.