On the origin of the two thermally driven relaxations in diluted spin ice Dy(1.6)Y(0.4)Ti2O7.

ABSTRACT

We report quantitative analysis of the ac susceptibility of the diluted spin ice compound Dy(1.6)Y(0.4)Ti(2)O(7), by fitting the frequency spectra of the two observed relaxation modes with a double Cole-Cole formula. Our results suggest that both modes are thermally activated, with the same intrinsic frequency, but different activation barriers. We propose that these thermally activated relaxation modes can be attributed to correlated spin clusters.