Projects / Programmes
Dielectric Study of Relaxor Ferroelectric P(VDF-TrFE) Copolymer System
Code |
Science |
Field |
Subfield |
1.02.01 |
Natural sciences and mathematics |
Physics |
Physics of condesed matter |
Code |
Science |
Field |
P190 |
Natural sciences and mathematics |
Mathematical and general theoretical physics, classical mechanics, quantum mechanics, relativity, gravitation, statistical physics, thermodynamics |
P250 |
Natural sciences and mathematics |
Condensed matter: structure, thermal and mechanical properties, crystallography, phase equilibria |
P260 |
Natural sciences and mathematics |
Condensed matter: electronic structure, electrical, magnetic and optical properties, supraconductors, magnetic resonance, relaxation, spectroscopy |
dielectric spectroscopy, copolymer, P(VDF-TrFE), relaxor, ferroelectric
Researchers (1)
no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
1. |
15644 |
PhD Vid Bobnar |
Physics |
Head |
2002 - 2004 |
362 |
Organisations (1)
no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
90,636 |
Abstract
Dielectric spectroscopy represents one of the basic experimental methods for studying the static and dynamic properties of relaxor systems, which have, due to their high values of dielectric and piezoelectric constant in a large temperature range, already found their utilization in many applications. Basic physical properties of relaxors also attract great interest, since it is believed that these systems provide a conceptual link between ferroelectrics and dipolar glasses.Recently, a giant electrostricitive response of the P(VDF-TrFE) copolymer, after its irradiation with high-energy electrons, has been observed, which makes it a very promissing material for applications such as sensors and actuators. After irradiation, copolymer exhibits typical relaxor behavior, suggesting that high-energy electrons break up all-trans chains in normal ferroelectric P(VDF-TrFE), which shows only low electrostricitive response, into nanopolar regions. An ultrahigh electrostrictive response therefore seems to be generated due to the large difference in lattice strain between the polar and nanopolar phases, however, intensive dielectric studies are necessary for a deeper understanding of its origin.The frequency and temperature dependence of the linear and nonlinear dielectric constant in copolymer P(VDF-TrFE), irradiated with high-energy electrons, will be studied. Results will show whether the same freezing process of the dielectric dynamics as in other relaxors occurs, and on their basis the microscopic origins for such high electrostrictive response will be deduced. Phase diagram with regard to the composition of both forming polymers, VDF and TrFE, will be constructed. Also, copolymers being irradiated with electrons of different energies will be investigated, in order to find out which copolymer is most useful for a specific application.In addition, dielectric studies of the P(VDF-TrFE) copolymer, irradiated with high-energy electrons, are also very interesting for the basic research, since this is the first known organic material showing a dispersion in the dielectric constant.