Muon Spin Relaxation and Susceptibility Studies of Pure and Doped Spin 1/2 Kagom\'{e}-like system (Cu$_x$Zn$_{1-x}$)$_{3}$V$_{2}$O$_7$(OH)$_{2}$ 2H$_2$O

TL;DR

This study investigates the magnetic behavior of pure and doped kagome-like systems using muon spin relaxation and susceptibility measurements, revealing persistent quantum fluctuations without static spin freezing down to very low temperatures.

Contribution

It provides new insights into the low-temperature spin dynamics of kagome systems, showing intrinsic quantum fluctuations and absence of static order in both pure and doped samples.

Findings

Persistent quantum spin fluctuations down to 50 mK

No static spin freezing observed in pure or doped samples

Fluctuating fields indicate intrinsic kagome network behavior

Abstract

Muon spin relaxation ($\mu$SR) and magnetic susceptibility measurements have been performed on the pure and diluted spin 1/2 kagom\'{e} system (Cu$_x$Zn$_{1-x}$)$_{3}$V$_{2}$O$_7$(OH)$_{2}$ 2H$_2$O. In the pure $x=1$ system we found a slowing down of Cu spin fluctuations with decreasing temperature towards $T \sim 1$ K, followed by slow and nearly temperature-independent spin fluctuations persisting down to $T$ = 50 mK, indicative of quantum fluctuations. No indication of static spin freezing was detected in either of the pure ($x$=1.0) or diluted samples. The observed magnitude of fluctuating fields indicates that the slow spin fluctuations represent an intrinsic property of kagom\'e network rather than impurity spins.