Spin fluctuations and anisotropic nuclear relaxation in single-crystal UPt3

Autor: MacLaughlin De, Bucher E, Vithayathil Jp, Koster E, Williams Dl
Rok vydání: 1991
Předmět:
Zdroj: Physical review. B, Condensed matter. 44(9)
ISSN: 0163-1829
Popis: The anisotropy and temperature dependence of the {sup 195}Pt spin-lattice relaxation rate {ital T} {sub 1}{sup {minus}1} have been measured in a single crystal of the heavy-fermion compound UPt{sub 3}. Between 1.5 and 4.2 K {ital T} {sub 1}{sup {minus}1} is proportional to temperature. The observed anisotropy {ital T} {sub 1( )}{sup {minus}1}/{ital T} {sub 1{perpendicular}}{sup {minus}1}=1.7{plus minus}0.1, together with the nearly isotropic {sup 195}Pt hyperfine field, imply that the spin fluctuations are predominantly in the basal plane. The Korringa product is close to the value expected for a noninteracting Fermi gas, which indicates that the relaxation is not enhanced by antiferromagnetic (AFM) fluctuations. The effective fluctuation rates derived from these NMR data (9{plus minus}1 meV) and from inelastic neutron scattering by AFM fluctuations are similar, indicating that a rate of this order characterizes a range of fluctuation wave vectors.
Databáze: OpenAIRE