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High-energy proton (3 MeV) irradiation with dosages ranging from 43 to 200 Mrad have been carried out to investigate the potential for modifying both the structure and property of vinylidene fluoride-trifluoroethylene 56/44 mol% copolymer. The structural and transitional behavior of the irradiated copolymer was studied by X- ray diffraction and differential scanning calorimetry. The polarization hysteresis, relative permittivity properties and electrostrictive strain response of these copolymers were also measured. It was found that the ferroelectric copolymer could be successfully converted to a relaxor at a low proton dosage of about 75 Mrad at ambient temperature. A slim polarization hysteresis loop and a frequency dispersion of the relative permittivity observed in the irradiated copolymer imply that the high-energy protons break up the coherent polarization domains in the ferroelectric copolymer into nanosized regions. In addition, the irradiation leads to a significant change in the ferroelectric-to-paraelectric phase transition behavior. X-ray diffraction measurements show that the crystalline region in the copolymer is converted into a nonpolar phase upon irradiation, and the lattice spacing increases significantly. The electric field induced phase transformation of the nanosized regions between the nonpolar and polar phase leads to a high electrostrictive strain observed in the irradiated copolymer. [ABSTRACT FROM AUTHOR]

Presents a study which measured the relative permittivity and loss of some type of nanocomposites with various volume fractions of ceramic as function of frequency and temperature. Fabrication of nanocomposites; Details on its dielectric behavior; Conclusion.

Studies on how the permittivities of 70/30 vinyledene fluoride-trifluoroethylene copolymer and lead zirconate titanate/vinyledene fluoride-triflouroethylene 0-3 composites have been measured at one kHz over the temperature range of 20 to 120 degrees centigrade. Fabrication of 0-3 composites; Permittivity measurements; Comparison with the bruggeman model; Estimation of the electric field acting on the ceramic particles inside a composite; Conclusions of the study.

This paper presents a magnetoelectric (ME) heterostructure of a magnetostrictive Terfenol-D/epoxy 0-3 composite (MSCP) plate combined with a piezoelectric PZT/epoxy 0-3 composite (PECP) plate along the longitudinal direction. By keeping the dimensions of the MSCP at 6.8 mm × 6.2 mm × 0.7 mm, heterostructures with various PECP lengths of 8-15 mm are prepared and characterized to reveal their frequency dependence of the ME effect. The results exhibit several resonance peaks in the heterostructures due to the magnetomechanical resonances (MMR) of the MSCP and the electromechanical resonances (EMR) of the PECP. The superposition of the MMR and EMR enhances significantly the ME output of the heterostructures. The highest ME voltage coefficient (αE) of 13.1 V/cm · Oe is observed at the resonance frequency of 106.8 kHz when the length ratio of the MSCP and PECP is set to 6.8/10.2, together with an optimal magnetic bias field of 0.7 kOe. [ABSTRACT FROM AUTHOR]

The spin orientation and spontaneous magnetostriction of multicomponent TbxDy1-x-yPry(Fe0.9B0.1)1.93 (0.10 ≤ x ≤ 0.25, 0.30 ≤ y ≤ 0.60) Laves phases were studied by step-scanning their (440) X-ray diffraction lines. The easy magnetization direction (EMD) of the, Laves phases changed from the «100» to «111» axis when x was increased from 0.10 to 0.25. With increasing y, the EMD of Tb0.15Dy0.85-yPry(Fe0.9B0.1)1.93 and Tb0.2Dy0.8-yPry(Fe0.9B0.1 )1.93 Laves phases `reoriented from the «100» to «111» axis. The magnetostriction coefficient λ111 of TbxDy1-x-yPry(Fe0.9B0.1)1.93 Layes phases increased with increasing x (or y) when y (or x) was kept constant. [ABSTRACT FROM AUTHOR]

The crystal structure, magnetization, and spontaneous magnetostriction of Tb1-xNdx(Fe0.9B0.1)2 alloys have been investigated. Xray diffraction (XRD) analysis shows that the alloys consist predominantly of the cubic Laves phase with a MgCu2-type structure for x ≤ 0.55. Increasing in lattice parameter and decreasing in Curie temperature with increasing z from 0 to 0.55 reveals an increment in the Nd content in the Laves phase. The (440) XRD line of the Laves phase splits doubly when x ≤ 0.7 because of a large spontaneous magnetostriction along its «111» easy magnetization direction. The magnetostriction coefficient Am decreases significantly with increasing x when 0 ≤ x ≤ 0.55. For x ≥ 0.7, it is difficult achieve saturation magnetization at room temperature due to increased amount of the Nd2Fe14B-type phase with large magnetocrystalline anisotropy. [ABSTRACT FROM AUTHOR]