Nanocomposites and nanomaterials

Electrocaloric and Pyroelectric properties of ferroelectric nanoparticles with size distributed according to the Truncated normal distribution
Hanna V. Shevliakova1, Anna N. Morozovska2, Nicholas V. Morozosky2, George S. Svechnikov1 and Vladimir V. Shvartsman3
1 Igor Sikorsky Kyiv Polytechnic Institute, Peremohy Ave, 37, Kyiv, 03056 Ukraine
E-mail: evro78@gmail.com
2 Institute of Physics of the NAS of Ukraine. Nauki Ave, 46, Kyiv-03039, Ukraine.
3 Institute for Materials Science and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 45141, Essen, Germany

Studies of low-dimensional ferroelectric (FE) materials are very relevant. Modern methods allow precise selection of nanoparticles (NPs) by size and shape, however as a rule, nanocomposites (NCs) contain NPs with distribution in size within certain limits around the average size. It is still unclear what effect this has on the electrocaloric (EC) and pyroelectric (PE) properties of NCs. The numerical and analytical models developed to date are mainly aimed at the description of NCs with NPs of the same size and certain shape [1].
This work based on [2]. There is consider theoretically an ensemble of the noninteracting spherical FE NPs with distributed sizes embedded in a polymer matrix. The model corresponds to a NCs with low concentration of the NPs. The aim of the work is to calculate and analyze the influence of the NPs size distribution function parameters on the polar, EC and PE properties of the ensemble, and corresponding hysteresis loops.
As a most widespread, Gaussian distribution truncated at minimal and maximal NPs radii are used in the calculations. For practical applications the dependence of PE figures of merit on the average NPs size for different parameters of the distribution function was calculated and briefly analyzed. 
Revealed effects of polar FE and EC properties of FE NPs present an interest for materials science, ferroelectricity and nanophysics.

1.	Morozovska A. N. et al. Analytical description of the size effect on pyroelectric and electrocaloric properties of ferroelectric nanoparticles // Phys. Rev. Mater.-2019.-3, N 10.-P. 104414
2.	Shevliakova H., Morozovska A., Morozosky N.., Svechnikov G., and Shvartsman V. The influence of the distribution function of ferroelectric nanoparticles sizes on their electrocaloric and pyroelectric properties // arXiv:2004.10871v1 [cond-mat]