Unlike proper ferroelectricity, the improper ferroelectricity in multiferroic rare-earth manganites h-ReMnO3 (Re=La-Lu,Y,Sc) thin films features a unique geometric distortion and stays immune to the depolarizing field in the ultra-thin limit. Here, we have managed to tune and boost ferroelectric geometric distortion of h-LuMnO3 thin films by doping Ca. Compressively strained h-Lu1-xCaxMnO3(x=0.1,0.2,0.3,0.4,0.5)epitaxial thin films were stabilized over sapphire substrates by a h-ScFeO3 buffer layer. When the doping concentration x>=0.2, the common substrate-induced interface clamping effect that suppresses improper ferroelectricity of h-ReMnO3 can be eliminated. This work establishes a potential quasi-2D ferroelectric system and suggests a general strain engineering method to enhance improper ferroelectricity of hexagonal manganites.
@article{arxiv.2408.03044,
title = {Enhance Ferroelectric Structural Distortion via Doping Ca in Epitaxial h-Lu1-xCaxMnO3 Thin Films},
author = {Detian Yang and Yaohua Liu and Xiaoshan Xu},
journal= {arXiv preprint arXiv:2408.03044},
year = {2024}
}
Comments
Main text 10 pages,8 figures; supplemental materials 5 pages, 3 figures