Low Temperature Spin Freezing in Dy2Ti2O7 Spin Ice

TL;DR

This study investigates the low temperature magnetic behavior of Dy2Ti2O7 spin ice, revealing a unique spin-freezing transition that differs from traditional spin glasses and highlights the effects of geometrical frustration.

Contribution

It provides new insights into the nature of spin freezing in spin ice, showing it as a distinct magnetic glassy state influenced by geometrical frustration.

Findings

Freezing temperature slightly increases with magnetic field.

Spin relaxation times remain narrowly distributed at low temperatures.

Relaxation time increases faster than exponentially at low temperatures.

Abstract

We report a study of the low temperature bulk magnetic properties of the spin ice compound Dy2Ti2O7 with particular attention to the (T < 4 K) spin freezing transition. While this transition is superficially similar to that in a spin glass, there are important qualitative differences from spin glass behavior: the freezing temperature increases slightly with applied magnetic field, and the distribution of spin relaxation times remains extremely narrow down to the lowest temperatures. Furthermore, the characteristic spin relaxation time increases faster than exponentially down to the lowest temperatures studied. These results indicate that spin-freezing in spin ice materials represents a novel form of magnetic glassiness associated with the unusual nature of geometrical frustration in these materials.