Anomalies in the Temperature Dependence of the Work Function of Ruthenium Faces (11bar 22) and (11bar 25)

This paper presents the dependence of the work function of ruthenium faces (11 2) and (11 5) as the result of experimental investigations by means of a thermionic microscope. Jumps of the work functions have been found at 1510 ± 10 K and 1530 plusmn; 10 K. The jump is 0.38 eV for the face (11 2) and 0.55 eV for the face (11 5). The anomalies found in the temperature dependence of the Ru work function are assumed to be caused by allotropic transformations. The values of effective work functions of Ru faces (11 2) and (11 5) are determined in the α-, β-, and γ-modifications. The micrographs of thermionic images of phase transformations are shown. The correlations between the volume and surface components of the work function are discussed.