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Electro-optic (EO) polymers offer a very attractive possibility of realizing low-cost microwave photonic components with a wide bandwidth and a low driving voltage, thanks to a low dispersion from microwave to optical frequency of polymeric materials on the one hand, and the progress in the synthesis of high hyperpolarizability chromophores on the other hand. This paper studies the influence of titanium dioxide (TiO) nanoparticle loading on the microwave and optical properties of EO polymers. Thus, poly(methyl methacrylate) (PMMA) and disperse red 1 (DR1) are used as host polymer and guest EO chromophore, respectively. With 1-3% TiO nanoparticle homogeneously incorporated in the polymer, the dielectric constant varies from 2.73 to 3.40 over the 400 MHz-10 GHz range, and the refractive index increases from 1.483 to 1.488 at the wavelength of 1539.6 nm. It is shown that fine tuning of dielectric constant and refractive index could allow improvement of the microwave photonic component bandwidth. For example, with an EO interaction length L = 2 cm (typical length of EO modulators), the ultimate modulator bandwidth could be raised to 258 GHz by loading PMMA-DR1 EO polymer with 1% wt of TiO nanoparticles. It is also found that loading polymer with nanoparticles could improve the EO response of poled polymers, represented by the intensity of the second-harmonic-generation (SHG) signal. The latter presents more than a threefold increase by loading PMMA-DR1 EO polymer with 2% wt TiO nanoparticles. [ABSTRACT FROM AUTHOR]

In this study, we report the magnetically induced electric field E in Pb(ZrTi)O (PZT) thin films, when they are subjected to both dynamic magnetic induction (magnitude B at 45 kHz) and static magnetic induction ( B) generated by a coil and a single permanent magnet, respectively. It is found that highest sensitivity to B- $$ {{\Delta \left| {E_{3} } \right|} \mathord{\left/ {\vphantom {{\Delta \left| {E_{3} } \right|} {\Delta B_{\text{dc}} }}} \right. \kern-0pt} {\Delta B_{\text{dc}} }} $$ -is achieved for the thin film with largest effective electrode. This magnetoelectric (ME) effect is interpreted in terms of coupling between eddy current-induced Lorentz forces (stress) in the electrodes of PZT and piezoelectricity. Such coupling was evidenced by convenient modelling of experimental variations of electric field magnitude with both B and B induction magnitudes, providing imperfect open circuit condition was considered. Phase angle of E versus B could also be modelled. At last, the results show that similar to multilayered piezoelectric-magnetostrictive composite film, a PZT thin film made with a simple manufacturing process can behave as a static or dynamic magnetic field sensor. In this latter case, a large ME voltage coefficient of $$ \alpha = {{\left| {E_{3} } \right|} \mathord{\left/ {\vphantom {{\left| {E_{3} } \right|} {B_{\text{ac}} }}} \right. \kern-0pt} {B_{\text{ac}} }} = 3.55\,{\text{V}}/{\text{cm}}\,{\text{Oe}} $$ under B = 0.3 T was found. All these results may provide promising low-cost magnetic energy harvesting applications with microsized systems. [ABSTRACT FROM AUTHOR]

A fluorine-oxygen substitution has been realized in a PZT material with a composition Pb0.89(Ba, Sr)0.11(Zr0.52Ti0.48)O3 thanks to the introduction of Mg2+ ions in the B-site of the perovskite. Oxygen vacancies may exist in the anionic sublattice if the fluorine rate is lower than the required one for a stoichiometric PZT-type ABO3. The F–O substitution makes the relative amount of rhombohedral phase in the MgO and F-doped PZT samples decrease and a drastic increase of the Curie temperature is observed. Minimum values of dielectric constant, high level dielectric losses and piezoelectric coefficient are obtained for a fluorine concentration close to the stoichoimetric PZT one. [ABSTRACT FROM AUTHOR]