Slow spin relaxation in a highly polarized cooperative paramagnet

TL;DR

This study investigates slow spin relaxation phenomena in a highly polarized cooperative paramagnet, revealing unusually slow dynamics linked to dipolar correlations through susceptibility measurements.

Contribution

It provides new insights into slow spin relaxation mechanisms in cooperative paramagnets, highlighting the role of dipolar correlations in these dynamics.

Findings

Observed very slow spin relaxations below 1 Hz

Suspected link between dipolar correlations and relaxation behavior

Demonstrated similar behavior in related materials

Abstract

We report measurements of the ac susceptibility of the cooperative paramagnet Tb2Ti2O7 in a strong magnetic field. Our data show the expected saturation maximum in chi(T) and also an unexpected low frequency dependence (< 1 Hz) of this peak, suggesting very slow spin relaxations are occurring. Measurements on samples diluted with nonmagnetic Y3+ or Lu3+ and complementary measurements on pure and diluted Dy2Ti2O7 strongly suggest that the relaxation is associated with dipolar spin correlations, representing unusual cooperative behavior in a paramagnetic system.