Lattice-Stiffening Transition in Copolymer Films of Vinylidene Fluoride (70%) with Trifluoroethylene (30%)

Journal Article · Mon Nov 29 04:00:00 EST 1999 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.83.4562· OSTI ID:20217980

Borca, C N ^[1]; Adenwalla, S ^[1]; Choi, Jaewu ^[1]; Sprunger, P T ^[2]; Ducharme, Stephen ^[1]; Robertson, Lee ^[3]; Palto, S P ^[4]; Liu, Jianglai ^[1]; Poulsen, Matt ^[1]; Fridkin, V M ^[4]

---

1. Department of Physics and Astronomy and the Center for Materials Research and Analysis, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States)
2. Center for Advanced Microstructure and Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, Louisiana 70806 (United States)
3. High Flux Isotope Reactor (HFIR), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
4. Institute of Crystallography, The Russian Academy of Sciences, 59 Leninsky Prospekt, 117333 Moscow, Russia (Russian Federation)

We report the discovery of a compressibility phase transition at 160 K in crystalline copolymer films of vinylidene fluoride (70% ) with trifluoroethylene (30% ). This phase transition is distinct from the known bulk ferroelectric-paraelectric phase transition at 353 K and surface ferroelectric phase transition at 295 K. The new phase transition is characterized by an increase in the effective Debye temperature from 48 to 245 K along the <010> direction as the temperature falls below 160 K. This phase transition is evident in neutron scattering, x-ray diffraction, angle-resolved photoemission, and in the dipole active phonon modes in electron energy-loss spectroscopy. (c) 1999 The American Physical Society.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• OSTI ID: 20217980
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 22 Vol. 83; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPRESSIBILITY
COPOLYMERS
DEBYE TEMPERATURE
ELECTRON-PHONON COUPLING
ENERGY-LOSS SPECTROSCOPY
EXPERIMENTAL DATA
HFIR REACTOR
NEUTRON DETECTION
PHASE TRANSFORMATIONS
PHOTOEMISSION
THIN FILMS
X-RAY DIFFRACTION