The Dilemma of CrIIINiII Exchange Interactions: Ferromagnetism versus Antiferromagnetism

Authors

  • Daniel Aravena,

    1. Departament de Química Inorgànica and Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)
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  • Prof. Eliseo Ruiz

    Corresponding author
    1. Departament de Química Inorgànica and Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)
    • Departament de Química Inorgànica and Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)
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Abstract

The sign of the exchange interaction in dinuclear CrIIINiII complexes was analyzed using theoretical methods based on density functional theory. This approach allowed us to reproduce the experimental J values correctly. In addition, the Kahn–Briat model, which uses the square of the sum of the overlaps between the magnetic orbitals to correlate with the exchange coupling constant, provided a reasonable correlation between the different types of CrIIINiII complexes when using biorthogonalized orbitals. We also examined the exchange interactions in two polynuclear CrIIINiII complexes: a Cr7Ni ring and an S-shaped Cr12Ni3 complex. We concluded that both systems exhibit antiferromagentic interactions, and that the CrIII⋅⋅⋅NiII interactions are similar in value to the CrIII⋅⋅⋅CrIII exchange couplings.

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