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Exchange interaction in the insulating phase of RNiO3
J-S Zhou1, J B Goodenough, B Dabrowski
1Texas Materials Institute, University of Texas at Austin, 1 University Station, C2201, Austin, Texas 78712, USA.
Physical Review Letters
|October 4, 2005
Summary
Researchers studied antiferromagnetic interactions in RNiO3 perovskites by measuring the pressure dependence of Néel temperature. Perturbation theory accurately describes these interactions below the insulator-metal transition temperature but fails near it.
Area of Science:
- Solid State Physics
- Materials Science
- Magnetism
Background:
- RNiO3 perovskites exhibit Type-E' antiferromagnetic order.
- Understanding spin-spin exchange interactions is crucial for characterizing magnetic properties.
- The insulator-metal transition temperature (T(IM)) influences magnetic ordering.
Purpose of the Study:
- To characterize spin-spin exchange interactions in inhomogeneous RNiO3 perovskites.
- To investigate the pressure dependence of Néel temperature (T(N)) relative to T(IM).
Main Methods:
- Systematic measurement of the pressure dependence of Néel temperature (T(N)).
- Study of RNiO3 perovskite samples with varying T(N) relative to T(IM).
Main Results:
- Spin-spin exchange interactions were characterized for samples with T(N)
- Perturbation theory successfully describes interatomic exchange interactions for T(N)
- Perturbation theory breaks down as T(N) approaches T(IM).
- Perturbation theory successfully describes interatomic exchange interactions for T(N)
Conclusions:
- The applicability of perturbation theory for describing exchange interactions is limited near the insulator-metal transition.
- Spin-spin exchange interactions in RNiO3 perovskites are sensitive to the proximity of the insulator-metal transition.
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