Phase transition of nano-sized amorphous tungsten to a crystalline state

We study thermal-physical characteristics of nano-sized amorphous tungsten and of its oxide. It is shown that a nano-size amorphous metal gets into a nano-size crystalline state after heating up to temperatures much lower than the half-temperature of melting, which is typical for all nano-size amorphous materials. Phase transition of amorphous nano-size WO 2 into crystalline state occurs in the temperature range 350–520°C, while the same transition in case of W takes place in the range 1000–1370°C. The energy released at crystallization of nano-size amorphous metal amounts to 170±25 J/g coinciding practically with the value of specific melting heat of usual tungsten. Such a high additional energy of nano-size amorphous metals above the energy of nano-size crystalline metals is their main peculiarity which widens essentially the range of their practical applications.