@article{10902/28255,
year = {2012},
month = {4},
url = {https://hdl.handle.net/10902/28255},
abstract = {High-pressure optical-absorption measurements performed in CuWO4 up to 20 GPa provide experimental evidence of the persistence of the Jahn-Teller (JT) distortion in the whole pressure range both in the low-pressure triclinic and in the high-pressure monoclinic phase. The electron-lattice couplings associated with the eg(E⊗e) and t2g(T⊗e) orbitals of Cu2+ in 
CuWO4 are obtained from correlations between the JT distortion of the CuO6 octahedron and the associated structure of Cu2+ d-electronic levels. This distortion and its associated JT energy (EJT) decrease upon compression in both phases. However, both the distortion and associated EJT increase sharply at the phase-transition pressure (PPT=9.9  GPa), and we estimate that the JT distortion persists for a wide pressure range not being suppressed up to 37 GPa. These results shed light on the transition mechanism of multiferroic CuWO4, suggesting that the pressure-induced structural phase transition is a way to minimize the distortive effects associated with the toughness of the JT distortion.},
organization = {C.-Y. Tu is acknowledged for providing us the crystals used to perform the experiments. J. R.-F. is indebted
to the FPI research grant (BES-2008-002043) and thanks C. Renero-Lecuna for fruitful discussions on the spectroscopic data. The authors thank the financial support from the MICINN of Spain under Grants No. MAT2010-
21270-C04-01, No. MAT2008-06873-C02-01/02, and No. CSD2007-00045.},
publisher = {American Physical Society},
publisher = {Physical Review Letters, 2012, 108(16), 166402},
title = {Anomalous high-pressure Jahn-Teller behavior in CuWO4},
author = {Ruiz Fuertes, Javier and Segura, A. and Rodríguez González, Fernando and Errandonea, D. and Sanz Ortiz, Marta Norah},
}