Eur. Phys. J. B (2018) 91: 150
https://doi.org/10.1140/epjb/e2018-90133-6

Regular Article

Fixed volume effect on polar properties and phase diagrams of ferroelectric semi-ellipsoidal nanoparticles

¹ Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3, Krjijanovskogo, Kyiv 03142, Ukraine
² Institute of Magnetism, National Academy of Sciences of Ukraine and Ministry of Education and Science of Ukraine, Prospekt Vernadskogo 36a, Kyiv 03142, Ukraine
³ National Research University of Electronic Technology “MIET”, Moscow, Zelenograd, Russia
⁴ Institute for Bionic Technologies and Engineering, I.M. Sechenov First Moscow State Medical University, 2-4 Bolshaya Pirogovskaya st., Moscow 119991, Russia
⁵ Sikorsky Kyiv Polytechnic Institute, Prospekt Pobedi 37, Kyiv 03052, Ukraine
⁶ Department of Physics and CICECO – Materials Institute of Aveiro, University of Aveiro, 3810-193 Aveiro, Portugal
⁷ Scientific-Practical Materials Research Centre of NAS of Belarus, Minsk, Belarus
⁸ Institute for Materials Science and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitatsstrasse 15, 45141 Essen, Germany
⁹ Institute of Physics, National Academy of Sciences of Ukraine, 46, pr. Nauky, Kyiv 03028, Ukraine

^a e-mail: vladimir.shvartsman@uni-due.de
^b e-mail: anna.n.morozovska@gmail.com

Received: 5 March 2018
Received in final form: 1 May 2018
Published online: 4 July 2018

Abstract

For advanced applications in modern industry, it is very important to reduce the volume of ferroelectric nanoparticles without serious deterioration of their polar properties. In many practically important cases, the fixed volume (rather than the fixed size) corresponds to realistic technological conditions of nanoparticles fabrication. The letter is focused on the theoretical study of the behavior of ferroelectric polarization, paramagnetoelectric coefficient and phase diagrams of semi-ellipsoidal nanoparticles with a fixed volume V . Our approach combines the Landau-Ginzburg-Devonshire phenomenology, the classical electrostatics, and the elasticity theory. Our results show that the size effects on the phase diagrams and polarization of semi-ellipsoidal BiFeO₃ nanoparticles nontrivially depend on V . These findings provide a path to optimize the polar properties of nanoparticles by controlling their phase diagrams at a fixed volume.