BaZrO3 stability under pressure: The role of nonlocal exchange and correlation
Artikel i vetenskaplig tidskrift, 2020

The ground-stale structure of BaZrO3 is experimentally known to be cubic down to absolute zero. However, there exist several measured properties and experimental characterizations that earlier computational works have failed to accurately describe and explain within this cubic symmetry. Among these properties and observations are the dielectric constant and the parallel mean-squared relative displacement value that tracks the fluctuations in distance for Ba-O atom pairs. Previous density-functional theory (DFT) studies have resolved the issue by assuming that BaZrO(3 )undergoes a phase transition from cubic to tetragonal I4/mcm symmetry, possibly while forming a glasslike state that reflects cubic symmetry on average. In this paper, we show that the set of experimental results can indeed be satisfactorily explained by DFT entirely within the cubic symmetry. We find that past theory limitations arose from the choice of exchange-correlation-functional approximations and that the inclusion of Fock exchange in hybrids significantly improves the DFT performance. We also find that the inclusion of nonlocal correlation effects is beneficial. We conclude by making a prediction for the phase-transition pressure for the transition from cubic to tetragonal symmetry at zero kelvin.

Författare

Erik Jedvik Granhed

Chalmers, Fysik, Material- och ytteori

Göran Wahnström

Kondenserad materie- och materialteori

Per Hyldgaard

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

PHYSICAL REVIEW B

2469-9950 (ISSN) 2469-9969 (eISSN)

Vol. 101 22 224105

Styrkeområden

Nanovetenskap och nanoteknik (SO 2010-2017, EI 2018-)

Energi

Materialvetenskap

Ämneskategorier

Fysik

Teoretisk kemi

Den kondenserade materiens fysik

Fundament

Grundläggande vetenskaper

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1103/PhysRevB.101.224105

Mer information

Senast uppdaterat

2020-08-03