Uniaxial negative thermal expansion in the mullite- and borax-type PbAlBO<sub>4</sub> polymorphs
- Autor(en)
- Mathias Gogolin, M. Mangir Murshed, Martin Ende, Ronald Miletich, Thorsten M. Gesing
- Abstrakt
This study presents an investigation on the axial negative thermal expansion of α-PbAlBO4 and β-PbAlBO4. Polycrystalline and single-crystal samples were prepared by solid-state synthesis method, characterized by temperature- and pressure-dependent X-ray and neutron diffraction experiments. The axial negative linear compressibility (NLC) is known for the α-polymorph, although structurally different the β-polymorph also shows similar NLC phenomenon. The lattice thermal expansion was described using the first-order Grüneisen equation of state, where the vibrational energy was calculated using the Debye–Einstein-Anharmonicity model. The density functional theory (DFT)-based phonon density of states and Raman spectra helped to choose the characteristic frequency to model the metric parameters. Lattice thermal expansion was additionally simulated in the quasi-harmonic approximation using the plane-wave DFT approach at the PBEsol level. The apparent departure of the quasi-harmonic approximation model has been discussed in terms of associated thermodynamic functions. The interplay between the topology-induced negative cross-compliance and anisotropic Grüneisen parameter has been identified as the driving force for the axial negative linear compressibility and axial negative thermal expansion.
- Organisation(en)
- Institut für Mineralogie und Kristallographie
- Externe Organisation(en)
- Jacobs Universität Bremen
- Journal
- Journal of Materials Science
- Band
- 55
- Seiten
- 177-190
- Anzahl der Seiten
- 14
- ISSN
- 0022-2461
- DOI
- https://doi.org/10.1007/s10853-019-04013-6
- Publikationsdatum
- 03-2020
- Peer-reviewed
- Ja
- ÖFOS 2012
- 104011 Materialchemie, 105113 Kristallographie
- Schlagwörter
- ASJC Scopus Sachgebiete
- Mechanics of Materials, Mechanical Engineering, Materials Science(all)
- Link zum Portal
- https://ucris.univie.ac.at/portal/de/publications/uniaxial-negative-thermal-expansion-in-the-mullite-and-boraxtype-pbalbo4-polymorphs(b9290d26-fc83-45f5-8ba7-95b6773638f8).html