Autor según el artículo: Wang, Fei; Lang, Zhongling; Yan, Likai; Stroppa, Alessandro; Poblet, Josep M.; de Graaf, Coen;

Departamento: Química Física i Inorgànica

Autor/es de la URV: De Graaf, Cornelis / Poblet Rius, Josep Maria / Wang, Fei

Palabras clave: Single molecule Positive ions Polyoxometalates Polarization Permanent dipoles Molecules Modern theory of polarization Interconversions Ground state Ferroelectricity Ferroelectric property Experimental values Electric polarization Density functional theory studies Density functional theory

Resumen: A detailed study on the single-molecule ferroelectric property of Preyssler-type polyoxometalates (POMs), [M3+P5W30O110](12-) (M = La, Gd, and Lu), is performed by density functional theory calculations. Linked to one H2O molecule, the cation (M3+) encapsulated in the cavity of the Preyssler framework is off-centered, and it generates a permanent dipole, which is essential for a ferroelectric ground state. Accompanied with a 180 degrees rotation of H2O, the switching of M3+ between two isoenergetic sites on both sides of the cavity results in a calculated barrier of 1.15 eV for Gd3+, leading to the inversion of electric polarization. The height of the barrier is in good agreement with the experimentally measured barrier for the Tb3+ ion, whose ionic radius is similar to Gd3+. The total polarization value of the crystal is estimated to be 4.7 mu C/cm(2) as calculated by the modern theory of polarization, which is quite close to the experimental value. Considering that the order of contributions to the polarization is M3+-H2O > counter-cations (K+) > [P5W30O110](15-), the interconversion of M3+-H2O between the two isoenergetic sites is predicted to be the main origin of ferroelectricity with a polarization contribution of 3.4 mu C/cm(2); the K+ counter-cations contribute by 1.2 mu C/cm(2) and it cannot be disregarded, while the framework appears to contribute negligibly to the total polarization. Our study suggests that a suitable choice of M3+-H2O could be used to tune the single-molecule ferroelectricity in Preyssler-type polyoxometalates.

Áreas temáticas: Química Physics, applied Nanoscience & nanotechnology Materials science, multidisciplinary Materials science (miscellaneous) Materials science (all) Materiais General materials science General engineering Engineering (miscellaneous) Engineering (all) Engenharias iii Engenharias ii Ciências agrárias i Astronomia / física

Acceso a la licencia de uso: https://creativecommons.org/licenses/by/3.0/es/

Direcció de correo del autor: coen.degraaf@urv.cat josepmaria.poblet@urv.cat fei.wang@urv.cat

Identificador del autor: 0000-0001-8114-6658 0000-0002-4533-0623 0000-0001-5106-5793

Fecha de alta del registro: 2023-02-23

Volumen de revista: 9

Versión del articulo depositado: info:eu-repo/semantics/publishedVersion

Enlace a la fuente original: https://aip.scitation.org/doi/10.1063/5.0035778

URL Documento de licencia: http://repositori.urv.cat/ca/proteccio-de-dades/

Referencia al articulo segun fuente origial: Apl Materials. 9 (2):

Referencia de l'ítem segons les normes APA: Wang, Fei; Lang, Zhongling; Yan, Likai; Stroppa, Alessandro; Poblet, Josep M.; de Graaf, Coen; (2021). Density functional theory study of single-molecule ferroelectricity in Preyssler-type polyoxometalates. Apl Materials, 9(2), -. DOI: 10.1063/5.0035778

DOI del artículo: 10.1063/5.0035778

Entidad: Universitat Rovira i Virgili

Año de publicación de la revista: 2021

Tipo de publicación: Journal Publications