1. Lattice dynamics and Raman spectrum of BaZrO3 single crystals
- Author
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Philippe Veber, Danila Amoroso, Mario Maglione, Monica Ciomaga Hatnean, Geetha Balakrishnan, Mael Guennou, Jens Kreisel, Philippe Ghosez, Cong Xin, Constance Toulouse, Physics and Materials Science Research Unit, University of Luxemburg, Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Theoretical Materials Physics, Quantum Materials Center (Q-MAT), Université de Liège, CNR SPIN, Luminescence (LUMINESCENCE), Institut Lumière Matière [Villeurbanne] (ILM), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, University of Warwick [Coventry], This work was supported by the Innovative Training Networks (ITN) Marie Sklodowska-Curie Actions-European Joint Doctorate in Functional Material Research (EJD-FunMat) (Project No. 641640). DFT-based calculations have been performed on the NIC4 cluster hosted at the University of Liège, within the ‘Consortium des Équipements de Calcul Intensif’ (CÉCI), funded by F.R.S-FNRS (Grant No. 2.5020.1) and by the Walloon Region. C.T., M.G., J.K. acknowledge financial support from the Fond National de Recherche Luxembourg through a PEARL Grant (No. FNR/P12/4853155/Kreisel). The work at the University of Warwick was supported by the EPSRC, UK (Grant No. EP/M028771/1)., Fonds National de la Recherche - FnR [sponsor], EPSCR [sponsor], and Luxembourg Institute of Science & Technology - LIST [research center]
- Subjects
Materials science ,Phonon ,Physics [G04] [Physical, chemical, mathematical & earth Sciences] ,FOS: Physical sciences ,02 engineering and technology ,Cubic crystal system ,01 natural sciences ,symbols.namesake ,Condensed Matter::Materials Science ,[SPI]Engineering Sciences [physics] ,Phase (matter) ,0103 physical sciences ,[CHIM]Chemical Sciences ,010306 general physics ,QC ,Perovskite (structure) ,[PHYS]Physics [physics] ,Condensed Matter - Materials Science ,Condensed matter physics ,Materials Science (cond-mat.mtrl-sci) ,Atmospheric temperature range ,021001 nanoscience & nanotechnology ,Physique [G04] [Physique, chimie, mathématiques & sciences de la terre] ,Octahedron ,symbols ,0210 nano-technology ,Raman spectroscopy ,Raman scattering - Abstract
${\mathrm{BaZrO}}_{3}$ is a perovskite that remains in the simple cubic phase at all temperatures, hence with no first-order Raman-active phonon mode allowed by symmetry. Yet, it exhibits an intense Raman spectrum with sharp and well-defined features. Here, we report the evolution of the Raman spectrum of ${\mathrm{BaZrO}}_{3}$ single crystals in a broad temperature range (4--1200 K) and discuss its origin with the support of detailed first-principle calculations of the lattice dynamics. Phonon calculations are performed not only for the cubic phase of ${\mathrm{BaZrO}}_{3}$, but also for the low-symmetry phases with octahedra tilts that have been suspected to exist at the nanoscale. We show that the Raman spectrum shows no direct evidence for these nanodomains, but can instead be explained by classical second-order Raman scattering. We provide an assignment of the dominant features to phonon mode combinations. In particular, we show that the high frequency range of the spectrum is dominated by overtones and shows an image of the phonon density of states corresponding to the stretching modes of the oxygen octahedra.
- Published
- 2019
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