Strain Effects in SrHfO$_{3}$ Films Grown by Hybrid Molecular Beam Epitaxy

Bibliographic Details
Title: Strain Effects in SrHfO$_{3}$ Films Grown by Hybrid Molecular Beam Epitaxy
Authors: Gemperline, Patrick T., Thind, Arashdeep S., Tang, Chunli, Sterbinsky, George E., Kiefer, Boris, Jin, Wencan, Klie, Robert F., Comes, Ryan B.
Source: ACS Appl. Electron. Mater. 2025, 7, 3, 983-996
Publication Year: 2024
Collection: Condensed Matter
Subject Terms: Condensed Matter - Materials Science
More Details: Perovskite oxides hetero-structures are host to a large number of interesting phenomena such as ferroelectricity and 2D-superconductivity. Ferroelectric perovskite oxides have been of significant interest due to their possible use in MOSFETs and FRAM. SrHfO$_3$ (SHO) is a perovskite oxide with pseudo-cubic lattice parameter of 4.1 $\mathring{A}$ that previous DFT calculations suggest can be stabilized in a ferroelectric P4mm phase, similar to STO, when stabilized with sufficient compressive strain. Additionally, it is insulating, possesses a large band gap, and a high dielectric constant, making it an ideal candidate for oxide electronic devices. In this work, SHO films were grown by hybrid molecular beam epitaxy with a tetrakis(ethylmethylamino)hafnium(IV) source on GdScO$_3$ and TbScO$_3$ substrates. Equilibrium and strained SHO phases were characterized using X-ray diffraction, X-ray absorption spectroscopy, and scanning transmission electron microscopy to determine the perovskite phase of the strained films, with the results compared to density functional theory models of phase stability versus strain. Contrary to past reports, we find that compressively-strained SrHfO$_3$ undergoes octahedral tilt distortions and most likely takes on the I4/mcm phase with the a$^0$a$^0$c$^-$ tilt pattern.
Comment: 36 pages, 11 figures
Document Type: Working Paper
DOI: 10.1021/acsaelm.4c01595
Access URL: http://arxiv.org/abs/2409.13066
Accession Number: edsarx.2409.13066
Database: arXiv
More Details
DOI:10.1021/acsaelm.4c01595