Anomalous high-pressure Jahn-Teller behavior in CuWO4
J Ruiz-Fuertes1, A Segura, F Rodríguez
1Departamento de Física Aplicada-ICMUV, Universitat de València, Edificio de Investigación, c/ Dr. Moliner 50, 46100 Burjassot, Valencia, Spain. javier.ruiz-fuertes@uv.es
Physical Review Letters
|June 12, 2012
Summary
The Jahn-Teller (JT) distortion in copper tungstate (CuWO4) persists under high pressure, even across structural phase transitions. This persistent JT distortion influences the material's multiferroic properties and transition mechanisms.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Solid State Chemistry
Background:
- Copper tungstate (CuWO4) exhibits complex electronic and structural properties.
- The Jahn-Teller (JT) effect is a key phenomenon influencing the behavior of transition metal compounds.
- Understanding pressure-induced phase transitions is crucial for materials design.
Purpose of the Study:
- To investigate the persistence and behavior of Jahn-Teller (JT) distortion in CuWO4 under high pressure.
- To elucidate the role of JT distortion in the pressure-induced structural phase transition of CuWO4.
- To correlate electron-lattice couplings with the JT distortion and electronic structure.
Main Methods:
- High-pressure optical-absorption measurements up to 20 GPa.
- Analysis of electron-lattice couplings using correlations between JT distortion and d-electronic levels.
- Estimation of JT distortion persistence up to 37 GPa.
Main Results:
- Experimental evidence confirms the persistence of JT distortion in both low-pressure triclinic and high-pressure monoclinic phases of CuWO4.
- The JT distortion and associated JT energy (E(JT)) decrease with compression in both phases.
- A sharp increase in distortion and E(JT) occurs at the phase-transition pressure (9.9 GPa), with JT distortion persisting up to at least 37 GPa.
Conclusions:
- The pressure-induced structural phase transition in CuWO4 serves to minimize the effects of the robust JT distortion.
- The findings provide insights into the transition mechanism of multiferroic CuWO4.
- The study highlights the significant role of JT distortion in the pressure-dependent behavior of CuWO4.
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