Spin Susceptibility and Superexchange Interaction in the Antiferromagnet CuO

TL;DR

This paper demonstrates that CuO exhibits quasi one-dimensional antiferromagnetic behavior, supported by experimental susceptibility measurements and theoretical modeling, revealing unexpected low-dimensional magnetic properties in a seemingly 3D structure.

Contribution

The study provides experimental evidence and theoretical analysis confirming CuO as a quasi 1D antiferromagnet within the Heisenberg model framework.

Findings

CuO's spin susceptibility matches 1D S=1/2 AFH model predictions

Experimental NMR data supports quasi 1D antiferromagnetism

Semi-quantitative explanation for CuO's low-dimensional behavior

Abstract

Evidence for the quasi one-dimensional (1D) antiferromagnetism of CuO is presented in a framework of Heisenberg model. We have obtained an experimental absolute value of the paramagnetic spin susceptibility of CuO by subtracting the orbital susceptibility separately from the total susceptibility through the $^{63}$Cu NMR shift measurement, and compared directly with the theoretical predictions. The result is best described by a 1D $S=1/2$ antiferromagnetic Heisenberg (AFH) model, supporting the speculation invoked by earlier authors. We also present a semi-quantitative reason why CuO, seemingly of 3D structure, is unexpectedly a quasi 1D antiferromagnet.