Spin glassiness and power law scaling in a quasi-triangular spin-1/2 compound

TL;DR

This study investigates magnetic properties of layered quasi-triangular spin-1/2 antiferromagnetic compounds, revealing spin-glass behavior and power law scaling, with a focus on the effects of zinc substitution and organic derivatives.

Contribution

It demonstrates the presence of spin-glass behavior and power law scaling in quasi-triangular spin-1/2 compounds, highlighting the effects of chemical substitution and organic derivatives.

Findings

Long-chain compounds exhibit spin-glass behavior without dilution.

DC susceptibility shows a crossover between two power law regimes.

Specific heat indicates phase transition in unintercalated compounds and glassy behavior in long-chain derivatives.

Abstract

We present data on the magnetic properties of two classes of layered spin S=1/2 antiferromagnetic quasi-triangular lattice materials: $Cu_{2(1-x)}Zn_{2x}(OH)_3NO_3$ ($0 < x < 0.65$) and its long chain organic derivatives $Cu_{2(1-x)}Zn_{2x}(OH)_3(C_7H_{15}COO)\cdot mH_2O$ ($0 < x < 0.29$), where non-magnetic Zn substitutes Cu isostructurally. It is found that the long-chain compounds, even in a clean system in the absence of dilution, $x\!=\!0$, show spin-glass behavior, as evidenced by DC and AC susceptibility, and by time dependent magnetization measurements. A striking feature is the observation of a sharp crossover between two successive power law regimes in the DC susceptibility above the freezing temperature. Specific heat data are consistent with a conventional phase transition in the unintercalated compounds, and glassy behavior in the long chain compunds.