English

Isotope effect in quasi-two-dimensional metal-organic antiferromagnets

Strongly Correlated Electrons 2009-11-13 v2

Abstract

Although the isotope effect in superconducting materials is well-documented, changes in the magnetic properties of antiferromagnets due to isotopic substitution are seldom discussed and remain poorly understood. This is perhaps surprising given the possible link between the quasi-two-dimensional (Q2D) antiferromagnetic and superconducting phases of the layered cuprates. Here we report the experimental observation of shifts in the N\'{e}el temperature and critical magnetic fields (ΔTN/TN4\Delta T_{\rm N}/T_{\rm N}\approx 4%; ΔBc/Bc4\Delta B_{\rm c}/B_{\rm c}\approx 4%) in a Q2D organic molecular antiferromagnets on substitution of hydrogen for deuterium. These compounds are characterized by strong hydrogen bonds through which the dominant superexchange is mediated. We evaluate how the in-plane and inter-plane exchange energies evolve as the hydrogens on different ligands are substituted, and suggest a possible mechanism for this effect in terms of the relative exchange efficiency of hydrogen and deuterium bonds.

Keywords

Cite

@article{arxiv.0807.1506,
  title  = {Isotope effect in quasi-two-dimensional metal-organic antiferromagnets},
  author = {P. A. Goddard and J. Singleton and C. Maitland and S. J. Blundell and T. Lancaster and P. J. Baker and R. D. McDonald and S. Cox and P. Sengupta and J. L. Manson and K. A. Funk and J. A. Schlueter},
  journal= {arXiv preprint arXiv:0807.1506},
  year   = {2009}
}
R2 v1 2026-06-21T10:59:00.385Z