Giant spin canting in the S = 1/2 antiferromagnetic chain [CuPM(NO3)2(H2O)2]n observed by 13C-NMR

TL;DR

This study combines experimental NMR measurements and theoretical calculations to reveal a significant spin canting phenomenon in a one-dimensional S=1/2 antiferromagnetic chain, with detailed insights into its temperature and magnetic field dependence.

Contribution

The paper demonstrates the observation of giant spin canting in a 1D antiferromagnetic chain using NMR and confirms it with exact diagonalization, providing new understanding of magnetic anisotropy.

Findings

Giant spin canting of 52 degrees at 10 K and 9.3 T

Excellent agreement between experimental data and theoretical calculations

Identification of staggered transverse magnetization in the material

Abstract

We present a combined experimental and theoretical study on copper pyrimidine dinitrate [CuPM(NO3)2(H2O)2]n, a one-dimensional S = 1/2 antiferromagnet with alternating local symmetry. From the local susceptibility measured by NMR at the three inequivalent carbon sites in the pyrimidine molecule we deduce a giant spin canting, i.e., an additional staggered magnetization perpendicular to the applied external field at low temperatures. The magnitude of the transverse magnetization, the spin canting of 52 degrees at 10 K and 9.3 T and its temperature dependence are in excellent agreement with exact diagonalization calculations.