Unveiling the role of the lone electron pair in sesquioxides at high pressure: compressibility of β-Sb2O3
| Autor: | A. L. J. Pereira, Juan Angel Sans, Catalin Popescu, Julio Pellicer-Porres, Francisco Javier Manjón, Javier Ruiz-Fuertes, Jordi Ibáñez, Vanesa P. Cuenca-Gotor, Julia Contreras-García, Virginia Monteseguro, Alfonso Muñoz, Plácida Rodríguez-Hernández |
|---|---|
| Přispěvatelé: | Ministerio de Economía y Competitividad (España), European Commission, Ibáñez Insa, Jordi, Ibáñez Insa, Jordi [0000-0002-8909-6541] |
| Rok vydání: | 2021 |
| Předmět: |
Raman scattering
Phase transition Materials science Phonon Ab initio Thermodynamics 02 engineering and technology Valentinite 01 natural sciences Vibrational properties Inorganic Chemistry Sb2O3 Phase (matter) 0103 physical sciences 010302 applied physics Electron pair Structural properties Compressibility 021001 nanoscience & nanotechnology X-ray diffraction High pressure Electronic properties FISICA APLICADA X-ray crystallography 0210 nano-technology Electronic density |
| Zdroj: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia instname Digital.CSIC. Repositorio Institucional del CSIC |
| ISSN: | 1477-9234 1477-9226 |
| Popis: | The structural, vibrational and electronic properties of the compressed beta-Sb2O3 polymorph, a.k.a. mineral valentinite, have been investigated in a joint experimental and theoretical study up to 23 GPa. The compressibility of the lattice parameters, unit-cell volume and polyhedral unit volume as well as the behaviour of its Raman- and IR-active modes under compression have been interpreted on the basis of ab initio theoretical simulations. Valentinite shows an unusual compressibility up to 15 GPa with four different pressure ranges, whose critical pressures are 2, 4, and 10 GPa. The pressure dependence of the main structural units, the lack of soft phonons, and the electronic density charge topology address the changes at those critical pressures to isostructural phase transitions of degree higher than 2. In particular, the transitions at 2 and 4 GPa can be ascribed to the changes in the interaction between the stereochemically-active lone electron pairs of Sb atoms under compression. The changes observed above 10 GPa, characterized by a general softening of several Raman- and IR-active modes, point to a structural instability prior to the 1st-order transition occurring above 15 GPa. Above this pressure, a tentative new high-pressure phase (s.g. Pcc2) has been assigned by single-crystal and powder X-ray diffraction measurements. This research was partially supported by the MINECO (FIS2017-83295-P, MAT2016-75586-C4-1/2/3-P, PGC2018- 097520-A-100, RED and PID2019-106383GB-41/42/43), by the MALTA-CONSOLIDER TEAM network (RED2018-102612-T) and by the EU-FEDER. JAS acknowledges the Ramon y Cajal fellowship (RYC-2015-17482) for financial support. VM thanks the Juan de la Cierva Program (FJCI-2016-27291) and Beatriz Galindo Fellowship (BG20/00077) for financial support. We also thank the ALBA (2016091901 experiment) and DIAMOND light source (CY22223 experiment) for providing beamtime, and Mark Warren, Sarah Barnett and Dominik Daisenberger for their help in the single-crystal X-ray diffraction experiment under pressure. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|