title: Low energy nuclear spin excitations in Ho metal investigated by high resolution neutron spectroscopy.
abstract: We have investigated the low energy excitations in metallic Ho by high resolution neutron spectroscopy. We found at T = 3 K clear inelastic peaks in the energy loss and energy gain sides, along with the central elastic peak. The energy of this low energy excitation, which is 26.59 ± 0.02 μeV at T = 3 K, decreased continuously and became zero at TN ≈ 130 K. By fitting the data in the temperature range 100-127.5 K with a power law we obtained the power-law exponent β = 0.37 ± 0.02, which agrees with the expected value β = 0.367 for a three-dimensional Heisenberg model. Thus the energy of the low energy excitations can be associated with the order parameter.
authors.affiliation: Institut Laue-Langevin, 6 rue Joules Horowitz, BP 156, F-38042 Grenoble Cedex 9, France. chatterji@ill.fr
authors.forename: Tapan
authors.initials: T
authors.lastname: Chatterji
authors.forename: Niina
authors.initials: N
authors.lastname: Jalarvo