ESR Study of (C_5H_{12}N)_2CuBr_4

TL;DR

This ESR study investigates the magnetic properties of (C$_5$H$_{12}$N)$_2$CuBr$_4$ across multiple frequencies and temperatures, confirming a spin singlet ground state and analyzing crystallographic orientations without detecting structural transitions.

Contribution

The paper provides detailed ESR measurements at multiple frequencies and temperatures, revealing the magnetic ground state and crystallographic orientations of (C$_5$H$_{12}$N)$_2$CuBr$_4$.

Findings

No structural transitions detected down to 3.7 K.

Confirmation of a spin singlet ground state below 6.6 T.

Identification of two crystallographic orientations of magnetic sites.

Abstract

ESR studies at 9.27, 95.4, and 289.7 GHz have been performed on (C$_5$H$_{12}$N)$_2$CuBr$_4$ down to 3.7 K. The 9.27 GHz data were acquired with a single crystal and do not indicate the presence of any structural transitions. The high frequency data were collected with a polycrystalline sample and resolved two absorbances, consistent with two crystallographic orientations of the magnetic sites and with earlier ESR studies performed at 300 K. Below $B_{C1}=6.6$ T, our data confirm the presence of a spin singlet ground state.