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The magnetoelectric (ME) properties of PbZr0.65Ti0.35O3-BaFe12O19 (PZT-BaM) multiferroic ceramic composites have been investigated in this work. These materials, containing both the ferroelectric PZT and ferrimagnetic BaM phases, were prepared from the conventional solid-state reaction method, and their main (micro) structural characteristics are provided. The ME measurements were performed over wide frequency and temperature ranges, and the influence of the BaM content was appraised. An enhanced ME coefficient (alpha) was obtained for the applied magnetic field of 0.8 kOe, at 97 kHz. In addition, the results reveal a high thermal stability of alpha in the whole analyzed temperature range, showing that the studied PZT-based ceramic composites have great potential for practical applications., Postprint (author’s final draft)

Transmission spectra of PZN-0.12PT were measured from near UV to IR for both poled sample and unpoled sample. Transmission rates were improved significantly after poling. By analyzing the transmission spectra in the visible range, optical band gap and lattice phonon were determined. The existence of hydrogen in PZN-0.12PT single crystal grown by flux method was postulated based on evidence obtained by FTIR.

Transmission spectra of PZN-0.12PT were measured from near UV to IR for both poled sample and unpoled sample. Transmission rates were improved significantly after poling. By analyzing the transmission spectra in the visible range, optical band gap and lattice phonon were determined. The existence of hydrogen in PZN-0.12PT single crystal grown by flux method was postulated based on evidence obtained by FTIR.

Transmission spectra of PZN-0.12PT were measured from near UV to IR for both poled sample and unpoled sample. Transmission rates were improved significantly after poling. By analyzing the transmission spectra in the visible range, optical band gap and lattice phonon were determined. The existence of hydrogen in PZN-0.12PT single crystal grown by flux method was postulated based on evidence obtained by FTIR.

Transmission spectra of PZN-0.12PT were measured from near UV to IR for both poled sample and unpoled sample. Transmission rates were improved significantly after poling. By analyzing the transmission spectra in the visible range, optical band gap and lattice phonon were determined. The existence of hydrogen in PZN-0.12PT single crystal grown by flux method was postulated based on evidence obtained by FTIR.

Rising demands in design of metamaterials requires better understanding of coupling phenomena in composite systems. Materials exhibiting product properties have effective magnitude of physical constants surpassing those of naturally existing materials. In this manuscript, we conduct numerical modeling of laminated terfenol-D/PZT/terfenol-D magnetoelectric composites with sandwich structure coupled through elastic interactions across the bonding layer. Developed magnetoelectric model couples the piezoelectric and magnetostriction constitutive equations with Langevin theory for simulating the saturated elastic response in composites. Simulated results were found to be in good agreement with the experimental results. Based upon the developed model we predict 17% improvement of magnetoelectric coefficient for sandwich structure through proper rotation of polarization in individual layers. (C) 2010 American Institute of Physics. [doi:10.1063/1.3387815]

This document is a final technical report of the research program entitled 'Low Loss Substrates for Microwave Applications and Sol-Gel Processing of Superconductors. Systematic studies on low K oxide substrate materials suitable for epitaxial deposition of high Tc superconducting (HTSC) yttrium barium cuprate (YBCO) films and their microwave applications have been extended to oxide materials with magnetoplumbite structure, such as LaMgAl11O19, NdGaMgAl10O19, CaGa6Al6O19, and CaGa12O19. The unique capabilities of a laser heated pedestal growth (LHPG) system have been utilized for test growth of candidate materials in single crystal fiber form to determine structure, thermal, and dielectric properties and to make positive identification of twin free systems. Dielectric properties, thermal expansion coefficients, melting temperatures and growth feasibility were tested. Through successful collaboration thorough tests on the compatibility of the SAT films as buffer layer in MgO/YBCO system have been performed. Excellent epitaxial YBCO films with Jc of 10(exp 6) A/cu cm were reproducibly obtained. Mechanisms relating the bonding nature and the order disorder in complex perovskite niobates and tantalates that governing the characteristics of their dielectric properties were studied through collaboration with the microprobe Raman spectroscopy groups. Work on the Shannon ion polarizability model for predicting dielectric permittivity in solids is being continued. Newly compiled normalized ion polarizabilities which take into consideration apparent bonding strengths improve the predictive capability considerably.

The focus of this program has been upon producing and characterizing new functional materials whose properties can be fine tuned to provide eye sensor protection against laser threats and to suit a range of optoelectronic device applications. Material systems that maximize orientational anisotropy (for use in scattering mode systems) and systems that minimize orientational anisotropy (for use in high field modulators and field induced photorefractive applications) were both approached. Relaxor ferroelectric tungsten bronze single crystals (Sr,Ba)Nb2O6 and (Pb,Ba)Nb2O6 solid solution families and relaxor ferroelectric perovskite (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PI) families, were studied extensively. The unique capabilities of a laser heated pedestal growth (LHPG) system were utilized for growth of new materials in single crystal fiber form that produces crystals of long interaction length for optical wave in the crystal and high crystal perfection with maximized properties along chosen directions. Hc uniaxial pressing hot forging, or appropriate solid state reaction processing methods were used to produce transparent polycrystalline ceramics to provide low scattering high anisotropy ceramics or high scattering high anisotropy ceramics. This final report summarizes significant results produced from this program through combination of experimental and crystal chemistry approaches in this field, delineates conclusions drawn from the research, and provides recommendations for future research.