Magnetic-field and pressure phase diagram of the triangular lattice antiferromagnet CsCuCl$_3$ clarified by magnetic susceptibility measured with a proximity detector oscillator

TL;DR

This study investigates how pressure affects the magnetic susceptibility and phase diagram of CsCuCl$_3$, revealing pressure-induced phase changes and predicting a new phase at higher pressures through experimental and theoretical comparison.

Contribution

It provides the first detailed pressure-dependent magnetic susceptibility measurements of CsCuCl$_3$ and predicts a new Y-phase above 1.7 GPa based on experimental and theoretical analysis.

Findings

H_sat increases with pressure

Widening of the uud-phase at 0.7 GPa

Prediction of a new Y-phase above 1.7 GPa

Abstract

The effect of pressure ($P$) on magnetic susceptibility of CsCuCl$_3$ was examined in magnetic fields ($\rm \mu_0$$H$) of up to 51 T using a proximity detector oscillator (PDO), and the $H$-$P$ phase diagram of CsCuCl$_3$ was constructed over the saturation field ($H_{\rm sat}$). We found that, with increasing $P$, $H_{\rm sat}$ increases and the uud-phase that appeared at $P$ = 0.7 GPa widened. Based on comparison between the experimental and calculated $H$-$P$ phase diagrams, the Y-phase was predicted to appear above 1.7 GPa. The interchain antiferromagnetic exchange interaction in the $ab$-plane was evaluated and found to increase with increasing $P$, which is consistent with a previous study under high pressure [D. Yamamoto {\it et al.}, Nat. Commun. {\bf 12}, 4263 (2021).]. Moreover, an anomaly was observed below $P$ = 0.6 GPa just below $H_{\rm sat}$ and might be a new phase transition derived from nonlinear response caused by the PDO technique.