Temperature dependence of the work function of hafnium islands on tungsten

Two-dimensional islands of hafnium near {100} faces of tungsten and their terraces were examined by field electron microscopy. The two-dimensional sublimation energy of the islands was found to be 6.1 +/- 0.5 eV. The field electron emission from the islands grows with temperature, the effect being considerably greater than theoretically expected. The negative temperature coefficient of phi, alpha (T), for the islands was estimated at (4-6) x 10(-4) eV grad(-1) or more, whereas for pure tungsten alpha (T) was found to be 2 x 10(-5) eV grad(-1). (C) 2000 MAIK "Nauka/Interperiodica".