Low-temperature spin-wave excitations in nickel, by neutron triple-axis spectroscopy

This is the authors' abstract. We don't add key points for this paper.

Measurements have been made of the low-energy spin waves ({ν}<3 THz) in nickel at temperatures from liquid-helium temperatures up to room temperature. New data-analysis procedures, involving resolution convolutions on an International Computers Ltd. Distributed Array Processor (DAP) computer, have allowed the separation of the spin wave from phonon cross sections. The values deduced for the spin-wave stiffness (D=96±{}5 THz A² at T=1.5 K and D=95±{}3 THz A² at T=295 K) are seen to be in agreement with some previous estimates and differences from others are explained. In particular, the low-temperature value agrees with the magnetization results, showing that the spin waves can account for all of the observed magnetization changes.