The effect of pressure-induced structural transition on exchange interaction function and electronic structure in
N Kamali Sarvestani1, A Yazdani, S A Ketabi
1School of Physics, Damghan University, P.O. Box 36716-41167, Damghan, Iran. n_kamali@std.du.ac.ir.
Physical Chemistry Chemical Physics : PCCP
|October 22, 2014
Summary
This study develops models to analyze exchange anisotropy in gadolinium (Gd) and investigates its phase transition. Findings suggest potential for Kondo-like behavior in Gd under specific conditions.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Computational Materials Science
Background:
- Exchange anisotropy in magnetic materials arises from complex spin interactions.
- Gadolinium (Gd) exhibits unique electronic properties due to its f-electron shell.
- Understanding phase transitions is crucial for predicting material behavior under pressure.
Purpose of the Study:
- To develop theoretical models for analyzing exchange anisotropy in gadolinium.
- To investigate the pressure-induced hexagonal to rhombohedral phase transition in Gd.
- To explore the possibility of Kondo-like behavior in gadolinium-based systems.
Main Methods:
- Development of two models: mean field approximation and density functional theory (DFT).
- Calculation of exchange eigenvalue-eigenfunction for inter-ion interactions.
- First-principles DFT calculations using the Wien2K package with PBE + U approximation.
Main Results:
- Models successfully describe coupled spin-lattice subsystems and the removal of exchange anisotropy.
- Observed a pressure-induced phase transition from hexagonal to rhombohedral structure in Gd.
- Identified d-orbital leakage into f-orbitals and coincident principal directions in the rhombohedral phase.
Conclusions:
- The study provides a theoretical framework for understanding exchange anisotropy and phase transitions in Gd.
- The observed electronic structure changes in the rhombohedral phase predict the emergence of Kondo-like behavior.
- These findings open avenues for exploring novel magnetic phenomena in gadolinium and related materials.
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