Using high temperature expansions for the equal time correlator S(q) and static susceptibility χ(q) for the t-J model, we present evidence for quantum critical (QC), z=1, behavior at intermediate temperatures in a broad range of t/J ratio, doping, and temperatures. We find that the dynamical susceptibility is very close to the universal scaling function computable for the asymptotic QC regime, ...

Deuteron spin-lattice relaxation time (TJ measurements of binary mixtures 2,6-lut idine/D20 have been done near the lower critical solution point (Tc L), e = (T — Tg L)/Tc 10~. Singularities are observed at Tc L . The changes in the slope of Ti (H) = / ( T ) can be interpreted as due to the effect of concentration changes on Ty and simultaneously strong overlaping of H N M R signals from coexis...

Low-frequency spin fluctuation dynamics in paramagnetic spinel LiV(2)O(4), a rare 3d-electron heavy-fermion system, is investigated. A parametrized self-consistent renormalization (SCR) theory of the dominant AFM spin fluctuations is developed and applied to describe temperature and pressure dependences of the low-T nuclear spin-lattice relaxation rate 1/T(1) in this material. The experimental ...

The magnetic properties of Na(2)CuP(2)O(7) were investigated by means of (31)P nuclear magnetic resonance (NMR), magnetic susceptibility, and heat capacity measurements. We report the (31)P NMR shift, the spin-lattice [Formula: see text], and spin-spin (1/T(2)) relaxation rate data as a function of temperature T. The temperature dependence of the NMR shift K(T) is well described by the S = 1/2 ...

A method is proposed for direct mapping of spectral density functions of the rotational motions of H-X bond vectors, such as ‘H-“N, by measuring a set of NMR relaxation parameters. The well known and frequently measured relaxation parameters T, and T, probe the spectral density function J(o) at five frequencies: 0, WN, wn, in wN, and wu t wN. In this study, the longitudinal relaxation time T,( ...

The temperature variations of the 6 3 Cu, 6 5 Cu and 5 V N M R spectra and 5 V spin-lattice relaxation rate 1 / T have been measured in a thiospinel CuV 2 S 4 . Drastic changes in the spectra and relaxation rates were observed at the charge density wave (CDW) transition temperature. With decreasing temperature T, 1 /Ti decreases exponentially due to the C D W transition (75 K < T< 90 K). The en...

The carbon-13 spin-lattice relaxation times (T1) of glycine have been measured as a function of pD and concentration. Contrary to previously reported findings, no significant dependence was observed on either pD or concentration. In addition, the T1 values reported here are much longer than those published earlier. The discrepancies arise from the presence of paramagnetic impurities in the earl...

The proton N M R second moment and spin-lattice relaxation time for tetrapropylammonium bromide and iodide have been measured over a wide temperature range. A solid-solid phase transition related to the onset of cation tumbling was found for both salts and confirmed by DTA. In the low temperature phases methyl group reorientation was evidenced. For iodide a dynamic nonequivalence of the methyl ...

Cold acclimation induced an increase of spin-lattice relaxation time (T1) of proton nuclear magnetic resonance in rat brown adipose tissue with concomitant increase of water content, while heat acclimation did not effect T1 of this tissue, although its water content was significantly decreased. Temperature acclimation did not affect either T1 or water content of neck muscle.