Absence of magnetic ordering and field induced phase diagram in the Gadolinium Aluminium garnet

TL;DR

This study investigates the magnetic properties of Gd$_3$Al$_5$O$_{12}$ garnet at very low temperatures, revealing a persistent spin liquid state despite freezing, and compares its phase diagram to related compounds, highlighting the robustness of the spin liquid phase.

Contribution

It provides new insights into the magnetic behavior of Gd$_3$Al$_5$O$_{12}$, demonstrating the stability of its spin liquid state and its phase diagram's similarity to Gd$_3$Ga$_5$O$_{12}$, contrasting with pyrochlore lattices.

Findings

No magnetic transition observed down to lowest temperatures.

Presence of a spin liquid state despite freezing at 300 mK.

Phase diagram similar to Gd$_3$Ga$_5$O$_{12}$, indicating robustness of the spin liquid phase.

Abstract

The robustness of spin liquids with respect to small perturbations, and the way magnetic frustration can be lifted by slight changes in the balance between competing magnetic interactions remains a rich and open issue. We address this question through the study of the Gadolinium Aluminium garnet Gd$_3$Al$_5$O$_{12}$, a related compound to the extensively studied Gd$_3$Ga$_5$O$_{12}$. We report on its magnetic properties at very low temperature. We show that despite a freezing at about 300 mK, no magnetic transition is observed, suggesting the presence of a spin liquid state down to the lowest temperatures similarly to Gd$_3$Ga$_5$O$_{12}$, in spite of a larger ratio between exchange and dipolar interactions. Finally, the phase diagram as a function of field and temperature is strongly reminiscent from the one reported in Gd$_3$Ga$_5$O$_{12}$. This study reveals the robust nature of the spin liquid phase for Gd ions on the garnet lattice in stark contrast to Gd ions on the pyrochlore lattice for which a slight perturbation drives the compound into a range of magnetically ordered states.