Electron correlation effects in Ni from Compton spectroscopy

Abstract

We present Compton profile measurements on Ni single crystal [1 1 0] from room temperature (ferromagnetic state) up to temperatures above the Curie point of 358°C (paramagnetic state). The autocorrelation function B( r → ) , the Fourier transform of the momentum density, is used to interpret the results. A localized peak in B( r → ) , appearing in a characteristic lattice position in this direction, is diminished with increasing temperature indicating that correlation effects are gradually diminished with the transition of the material to the paramagnetic state.