The Nf-R curve for the gap lattice band and the electron spin reversion effect under a weak magnetic field

Abstract

The surface sensitivity of gallium phosphide was studied by measurement of the infrared fundamental lattice band profile, and the following effects are explained using the Nf-R curve which was derived successfully from the classical dispersion relation. For n-type material, with tellurium and sulphur impurities, the reflection profile of the (100)a plane is well explained by classical dispersion analysis, but that of the (100)b plane is impossible to treat since the profile is sensitivity modified by the treatment. In particular, under a weak magnetic field the change of reflectivity at the lattice band region (380 cm -1) is reversible with the polarity of the field. Classically, these effects are explained as being induced by the variation of the oscillator strength f in the Nf-R curve, relating to the spin reversion effect of the lone-paired electrons. Also, in the linear process of the interaction of the surface donor electrons and IR radiation, the statistical variation of the spin magnetic moment and hence excitation/transition probability is considered as an origin of the spin reversion effect. This effect is also verified by measurements of the reflectivity of ferromagnetic substances such as iron in the visible region.