1/T_1 nuclear relaxation time of \kappa-(BEDT-TTF)_ 2 Cu [N(CN)_2] Cl : effects of magnetic frustration

TL;DR

This study investigates how magnetic frustration influences the antiferromagnetic phase of an organic salt using a Heisenberg model and NMR data, revealing pressure and frustration effects on nuclear relaxation times.

Contribution

It introduces a theoretical analysis linking magnetic frustration and pressure effects to nuclear relaxation times in a specific organic salt.

Findings

Model qualitatively reproduces experimental suppression of 1/T_1

Pressure and magnetic frustration effects are closely related

Supports the role of magnetic frustration in nuclear relaxation dynamics

Abstract

We study the role played by the magnetic frustration in the antiferromagnetic phase of the organic salt \kappa-(BEDT-TTF)_ 2 Cu [N(CN)_2] Cl. Using the spatially anisotropic triangular Heisenberg model we analyze previous and new performed NMR experiments. We compute the 1/T_1 relaxation time by means of the modified spin wave theory. The strong suppression of the nuclear relaxation time observed experimentally under varying pressure and magnetic field is qualitatively well reproduced by the model. Our results suggest the existence of a close relation between the effects of pressure and magnetic frustration.