Crystal structure, magnetic and resonant properties of decorated spin kagome system (CsCl)Cu$_5$As$_2$O$_{10}$

TL;DR

This study synthesizes and characterizes a decorated spin kagome arsenate, revealing a structural phase transition near room temperature and a transition to a canted antiferromagnetic state at 21 K, with theoretical insights into exchange interactions.

Contribution

It provides the first detailed analysis of the crystal structure, magnetic properties, and theoretical exchange interactions of CsClCu5As2O10, a new kagome system with complex phase behavior.

Findings

Structural phase transition from trigonal to monoclinic near room temperature.

Transition to a canted antiferromagnetic state at 21 K.

Exchange interaction energy scale is intermediate among related compounds.

Abstract

We report the synthesis and investigation of the crystal structure and physical properties of the averievite-like arsenate, $(\mathrm{CsCl})\mathrm{Cu}_5\mathrm{As}_2\mathrm{O}_{10}$. Just above room temperature, this compound undergoes a structural phase transition from the high-temperature trigonal $P\bar{3}m1$ $(a=b=a_0$ and $c=c_0)$ to the low-temperature monoclinic $I2/a$ phase $(a \approx \sqrt{3}a_0$, $b=a_0$, $c \approx 2c_0$ and $\beta \approx 90.6^\circ)$. According to thermodynamic and nuclear magnetic resonance measurements, it experiences a phase transition into a canted antiferromagnetic state at $T_N = 21~\mathrm{K}$. The density functional theory calculations place the energy scale of kagome exchange interaction parameter in $(\mathrm{CsCl})\mathrm{Cu}_5\mathrm{As}_2\mathrm{O}_{10}$ in between those in V- and P-analogs.