Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effects of Strain and Film Thickness on the Stability of the
  Rhombohedral Phase of HfO2   The discovery of ferroelectric polarization in HfO2-based ultrathin films has
spawned a lot of interest due to their potential applications in data storage.
Recently, a new R3m rhombohedral phase was proposed to be responsible for the
emergence of ferroelectricity in the [111]-oriented Hf0.5Zr0.5O2 thin films,
but the fundamental mechanism of ferroelectric polarization in such films
remains poorly understood. In this paper, we employ density-functional-theory
calculations to investigate structural and polarization properties of the R3m
HfO2 phase. We find that the film thickness and in-plane compressive strain
effects play a key role in stabilizing the R3m phase leading to robust
ferroelectricity of [111]-oriented R3m HfO2.

8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph