Single crystal EPR analysis of pyrazine bridged layered complexes

ORAL

Abstract

Over the last three decades our group has endeavored to model the antiferromagnetic interactions of the copper-oxide high-temperature superconductors via crystal engineering of low dimensional copper(II) systems. Our efforts have led us to systems of the type [Cu(pz)2(L)2](A)2 which contain well isolated pyrazine-bridged square-lattices with Heisenberg antiferromagnetic superexchange. We report primarily on [Cu(pz)2(2-hydroxypyridine)2](PF6)2. The single crystal EPR linewidth as a function of temperature and angle at X-Band are investigated in three orientations where XYZ≈abc. The linewidth is investigated in terms of g-anisotropy, dipolar spin-diffusion, antisymmetric and anisotropic exchange. The linewidth in the ac and bc planes follow a cos2(θ) dependence indicating the dominant contributions to the linewidth are the anisotropic and antisymmetric exchange1. These results are compared to those from other techniques including NMR and SQUID magnetometry. The effects of these interactions on the 3D ordering temperature are considered.
References:
[1] A. Bencini, D. Gatteschi, EPR of Exchange Coupled Systems. Dover Edition., 2012

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Presenters

  • Jeffrey Monroe

    Chemistry, Clark University

Authors

  • Jeffrey Monroe

    Chemistry, Clark University

  • Christopher Landee

    Clark University, Physics, Clark University

  • Fredrick T Greenaway

    Chemistry, Clark University

  • Jan L Wikaira

    Chemistry, University of Canterbury

  • Mark M Turnbull

    Chemistry, Clark University