RELAXATION BEHAVIORS IN CLUSTER-GLASS PHASE OF ITINERANT MAGNETIC FEXTIS2 CRYSTALS STUDIED BY MAGNETOTRANSPORT MEASUREMENTS USING PULSED MAGNETIC-FIELDS

Time decays of Hall resistivities rho(H) using pulsed magnetic fields up to 20 T for a cluster-glass phase of FexTiS2 (x = 1/4, T-g= 53 K) have been measured over the temperature ranges 4.2-45 K and time ranges 10(-1)-10(3) s. The temperature and peak field dependences of rho(H) are analyzed to obtain a universal relationship, mT(alpha) = C phi(beta), for the parameters characterizing the dynamical properties, where m is an exponent for the power law rho(H)(t)=At--m after a field is switched off, alpha = - 1/2, and phi a newly introduced quantity, phi = [M(H-p) - M(r)(O)]/M(H-p) [M(H-p) is the magnetization at the peak field H-p and M(r)(O) the remanent magnetization at time t = O]. The exponent P has different values 0.60 and 2.9 for phi < phi(c) and phi > phi(c), respectively; phi(c) = 0.34, which corresponds to a three-dimensional 'critical volume fraction' in a site-percolation picture.