Magnetic field dependence of spin-glass freezing temperature in a diluted antiferromagnet Mn0.55Mg0.45TiO3

In order to examine magnetic properties of a spin-glass Mn0.55Mg0.45TiO3 un der magnetic fields, dc magnetization, ac susceptibility, muon spin relaxat ion (mu SR), and neutron scattering measurements have been performed. A fre ezing temperature observed by the dc magnetization and the ac susceptibilit y strongly depends on magnetic field, H. But for the latter, the H dependen ce becomes weak, as the measuring frequency increases. In the mu SR and the neutron scattering measurements, no significant field dependence is observ ed. These results demonstrate that the field dependence of the freezing tem perature becomes weaker, as the time scale of measurements shortens. (C) 20 01 American Institute of Physics.