Temperature-dependent growth of the Na/GaP(110) interface

The adsorption of Na onto GaP(110) is markedly different when the substrate is held below 120 K and above 140 K. At 120 K, the development of core and valence level photoemission spectra is consistent with charge transfer between the alkali metal and the surface atoms of a chemically undisrupted substrate. However, at 140 K, similar measurements show very different spectral changes, resembling more closely a reactive interface, involving interaction between the Na and bulk GaP atom