posted on 2017-05-26, 10:45authored byAmit KC, Pavel BorisovPavel Borisov, Vladimir V. Shvartsman, David Lederman
The orthorhombically distorted perovskite NaMnF3 has been predicted to become ferroelectric if an a = c distortion of the bulk Pnma structure is imposed. In order to test this prediction, NaMnF3 thin films were grown on SrTiO3 (001) single crystal substrates via molecular beam epitaxy. The best films were smooth and single phase with four different twin domains. In-plane magnetization measurements revealed the presence of antiferromagnetic ordering with weak ferromagnetism below the Néel temperature TN = 66 K. For the dielectric studies, NaMnF3 films were grown on a 30 nm SrRuO3 (001) layer used as a bottom electrode grown via pulsed laser deposition. The complex permittivity as a function of frequency indicated a strong Debye-like relaxation contribution characterized by a distribution of relaxation times. A power-law divergence of the characteristic relaxation time revealed an order-disorder phase transition at 8 K. The slow relaxation dynamics indicated the formation of super-dipoles (superparaelectric moments) that extend over several unit cells, similar to polar nanoregions of relaxor ferroelectrics.
Funding
This work was supported by the National Science Foundation
(grant # 1434897) and the WVU Shared Research Facilities.
History
School
Science
Department
Physics
Published in
Applied Physics Letters
Volume
110
Issue
9
Citation
KC, A. ... et al., 2017. Weak ferromagnetism and short range polar order in NaMnF3 thin films. Applied Physics Letters, 110, 092901; doi: 10.1063/1.4977421
Publisher
AIP Publishing
Version
AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
Acceptance date
2017-02-01
Publication date
2017
Notes
This paper was published in the journal, Applied Physics Letters and the definitive version is available at: http://dx.doi.org/10.1063/1.4977421 with supplementary information at: ftp://ftp.aip.org/epaps/appl_phys_lett/E-APPLAB-110-018709