Abstract
| Language | English |
|---|---|
| Pages | 1733-1742 |
| Number of pages | 10 |
| Journal | European Physical Journal - Special Topics |
| Volume | 225 |
| Issue number | 8 |
| Early online date | 18 Jul 2016 |
| DOIs | |
| Publication status | Published - 31 Oct 2016 |
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Keywords
- ferroelectric polymers
- poly(vinylidene difluoride)
- PVDF
- flexible electronic devices
- crystal structures
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A van der Waals density functional theory study of poly(vinylidene difluoride) crystalline phases. / Pelizza, F.; Smith, B.; Johnston, K.
In: European Physical Journal - Special Topics, Vol. 225, No. 8, 31.10.2016, p. 1733-1742.Research output: Contribution to journal › Article
TY - JOUR
T1 - A van der Waals density functional theory study of poly(vinylidene difluoride) crystalline phases
AU - Pelizza, F.
AU - Smith, B.
AU - Johnston, K.
PY - 2016/10/31
Y1 - 2016/10/31
N2 - Ferroelectric polymers, such as poly(vinylidene difluoride) (PVDF), have many potential applications in flexible electronic devices. PVDF has six experimentally observed polymorphs, three of which are ferroelectric. In this work we use density functional theory to investigate the structural properties, energetics and polarisation of the stable α-phase, its ferroelectric analogue, the δ-phase, and the β-phase, which has the best ferroelectric properties. The results from a variety of exchange and correlation functionals were compared and it was found that van der Waals (vdW) interactions have an important effect on the calculated crystal structures and energetics, with the vdW-DF functional giving the best agreement with experimental lattice parameters. The spontaneous polarisation was found to strongly correlate with the unit cell volumes, which depend on the functional used. While the relative phase energies were not strongly dependent on the functional, the cohesive energies were significantly underestimated using the PBE functional. The inclusion of vdW interactions is, therefore, important to obtain the correct lattice structures, polarisation and energetics of PVDF polymorphs.
AB - Ferroelectric polymers, such as poly(vinylidene difluoride) (PVDF), have many potential applications in flexible electronic devices. PVDF has six experimentally observed polymorphs, three of which are ferroelectric. In this work we use density functional theory to investigate the structural properties, energetics and polarisation of the stable α-phase, its ferroelectric analogue, the δ-phase, and the β-phase, which has the best ferroelectric properties. The results from a variety of exchange and correlation functionals were compared and it was found that van der Waals (vdW) interactions have an important effect on the calculated crystal structures and energetics, with the vdW-DF functional giving the best agreement with experimental lattice parameters. The spontaneous polarisation was found to strongly correlate with the unit cell volumes, which depend on the functional used. While the relative phase energies were not strongly dependent on the functional, the cohesive energies were significantly underestimated using the PBE functional. The inclusion of vdW interactions is, therefore, important to obtain the correct lattice structures, polarisation and energetics of PVDF polymorphs.
KW - ferroelectric polymers
KW - poly(vinylidene difluoride)
KW - PVDF
KW - flexible electronic devices
KW - crystal structures
UR - https://link.springer.com/article/10.1140%2Fepjst%2Fe2016-60133-8
U2 - 10.1140/epjst/e2016-60133-8
DO - 10.1140/epjst/e2016-60133-8
M3 - Article
VL - 225
SP - 1733
EP - 1742
JO - European Physical Journal - Special Topics
T2 - European Physical Journal - Special Topics
JF - European Physical Journal - Special Topics
SN - 1951-6355
IS - 8
ER -