Study of the momentum distribution of a Zn single crystal using neutron Compton scattering

Abstract

The neutron Compton scattering technique (NCS) was used for measuring the atomic momentum distribution, at ~4.6 K, of an hcp zinc single crystal in directions parallel and perpendicular to the hexagonal planes. A strong anisotropy has been observed and interpreted in terms of the anisotropic binding of the atoms in Zn. The data were used for deducing the zero-point mean-square atomic momenta p²_x and p²_z . These were combined with reported measured values of x² and z² obtained by the Mössbauer effect and used to test the predictions of the uncertainty principle for the two products p²_x x² and p²_z z² near 0 K. The measured values of p²_x and p²_z seem to conform to the requirements of the uncertainty relations to within 3%. The data are compared with those obtained using the nuclear resonance photon scattering (NRPS) technique.