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Electron transpiration cooling has previously been predicted to be an alternative cooling mechanism for leading edges of aerospace platforms traveling at extreme velocities, where thermoelectric materials shaped as leading edges manage heat loads. Here, thermo-electron emitting LaB6 ceramics with blunt edges were placed between two conical-shaped electrodes, and a plasma glow was ignited to heat the sample. Analysis of current–voltage (I–V) curves demonstrated that insertion of LaB6 into the plasma column resulted in an increase in the electron density of the plasma, evidencing thermally stimulated electron emission. With increasing sample temperature to 1200 K, Δne increased by ∼4 × 1010 #/cm3, the electron temperature (Te) decreased from ∼8 eV (1000 K) to 2.5 eV, and the emission begins to appear to become space charge-limited. Richardson's analysis of the temperature dependence of the electron emission in the region of ion saturation, yielded an activation energy consistent with the work function of LaB6. Modulation of the LaB6 surface temperature (ΔT = 10 K) and the plasma current (ΔI = 70 μA) under electric voltage (80 V) applied between the sample and current probe was demonstrated. The results show for the first time the feasibility of electron transpiration cooling effects under plasma conditions similar to that of aerothermal environments. [ABSTRACT FROM AUTHOR]

The coupling between magnetic and electric subsystems in composites of ferromagnetic and ferroelectric phases is a product property that is facilitated by mechanical strain that arises due to magnetostriction and the piezoelectric effect in the constituent phases. Such multiferroic composites are of immense interests for studies on the physics of electromagnetic coupling and for use in a variety of applications. Here, we focus on magneto-electric (ME) coupling in nanocomposites. Particular emphasis is on core-shell particles and coaxial fibers, thin film heterostructures, and planar structures with a variety of mechanical connectivity. A brief review of models that predict strong ME effects in nanostructures is followed by synthesis and characterization. Core-shell particulate composites can be prepared by hydrothermal processes and chemical or deoxyribonucleic acid-assisted assembly. Electrospinning techniques have been utilized to prepare defect free core-shell nanofibers. Core-shell particles and fibers can be assembled into superstructures with the aid of magnetic and electric fields and characterized for possible use in advanced technologies. Chemical-vapor deposition techniques have been shown to be effective for the preparation of heterostructures of ferrites and ferroelectrics. Exotic planar multiferroic structures with potential for enhancing ME coupling strengths are also considered. Scanning probe microscopy techniques are ideal for probing the nature of direct- and converse-ME coupling in individual nanostructures. Magnetoelectric characterization of assemblies of nanocomposites can be done by ME voltage coefficient, magnetic field induced polarization, and magneto-dielectric effects. We conclude with a brief discussion on possible avenues for strengthening the product properties in the nanocomposites. [ABSTRACT FROM AUTHOR]

The present work shows good control of both magnetic and electric properties with electric and magnetic fields, respectively, for epitaxial CoFe2O4 (CFO) films on Pb(Mg,Nb)O3-PbTiO3 (PMN-PT). X-ray reciprocal space mapping revealed a transformation between a- and c-domains in the PMN-PT under electric field (E). Magnetic hysteresis loop and magnetic force microscopy (MFM) measurements showed a considerable change in the magnetic properties in specific areas of CFO layers poled by MFM probe tips. Furthermore, a pulsed electric field applied to the substrate was found to switch the magnetization of CFO between high and low values, depending on the polarity of E. [ABSTRACT FROM AUTHOR]

We demonstrate a significant control of the polarization response under an applied magnetic field for a magnetoelectric (ME) heterostructure. This structure was comprised of a 2 μm thick ferroelectric BaTiO3 (BTO) film deposited on flexible ferromagnetic metallic glass foil (25 μm thick). Au was used as a buffer layer to control BTO growth orientation, and to protect the metallic glass from oxidation. x-ray diffraction and scanning electron microscopy demonstrated the successful growth of well-crystallized BTO films with a high degree of (111) orientation on the amorphous metallic glass foils. Well-defined polarization (P-E) and magnetization (M-H) hysteresis loops confirmed the coexistence of ferroelectric and ferromagnetic properties. A ME voltage coefficient of about ∼60 mV/cm Oe was measured. [ABSTRACT FROM AUTHOR]

A magnetoelectric composite consisting of a multilayer Pb(Zr,Ti)O3 piezoelectric (d33) stack and a magnetostrictive (Galfenol and/or Terfenol-D) rod assembled in a prestressed frame in a longitudinal-longitudinal configuration has been found to have a high magnetoelectric (ME) charge coupling to an applied magnetic field. Values of the ME charge coefficient as high as 16.4 nC/Oe (or 3.6×10-6 C/m2 Oe) were found at quasistatic frequencies and 123 nC/Oe (or 2.8×10-5 C/m2 Oe) under resonance drive, which are 100–1000 times higher than that previously reported for other ME laminates. [ABSTRACT FROM AUTHOR]

Structural phase transformations of [111] electric field cooled (FC) Pb(Mg1/3Nb2/3)O3–0.30PbTiO3 crystals have been performed by x-ray diffraction. A phase sequence of cubic (C)→tetragonal (T)→orthorhombic (O)→monoclinic (M) was found in the FC condition. The finding of a=b>c demonstrates that the M phase is of the MB type. [ABSTRACT FROM AUTHOR]

Laminated composite rings of magnetostrictive Terfenol-D (TbxDy1-xFe2) and piezoelectric Pb(Zr1-xTix)O3 have been analyzed and prototyped. A circumferentially magnetized and circumferentially polarized (or C-C) magnetoelectric (ME) mode was investigated. Analysis and measurements have shown that C-C laminated rings have a high ME voltage coefficient under an applied vortex magnetic field. [ABSTRACT FROM AUTHOR]

Magnetostrictive and piezoelectric laminate composites of terfenol-D and Pb(Zr[sub 1-x]Ti[sub x])O[sub 3] have been studied. The magnetoelectric (ME) coefficients have been characterized for the different operational modes: (i) a longitudinally magnetized and transversely polarized longitudinal transverse (LT) mode, and (ii) a transversely magnetized and transversely polarized transverse–transverse (TT) mode. The results demonstrate that the (LT) magnetoelectric mode has dramatically higher ME coefficients than the TT one. The LT magnetoelectric coefficient is up to 5–7 times larger than the TT one, when operated in low magnetic bias ranges. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The electromechanical performance characteristics of electrostrictive 0.9 Pb(Mg[sub 1/3]Nb[sub 2/3])O[sub 3]–0.1 PbTiO[sub 3] and piezoelectric 0.7 Pb(Mg[sub 1/3]Nb[sub 2/3])O[sub 3]–0.3 PbTiO[sub 3] ceramics have been investigated under uniaxial stress (σ). The results demonstrate that the large-signal electromechanical properties of electrostrictive ceramics are decreased with increasing σ, whereas those of the piezoelectric are increased but accompanied by significantly increased hysteretic losses. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Young’s modulus (Y) of 0.7Pb(Mg[sub 1/3]Nb[sub 2/3])O[sub 3]–0.3PbTiO[sub 3] has been investigated for polycrystals and single crystals oriented along <001>, <110>, and <111>. The value of Y[sub <001>] and Y[sub <110>] for single crystals was dramatically lower than either Y[sub <111>] or the polycrystalline averaged value. For ceramics, field dependent measurements revealed a significant softening of Y, which was not observed for oriented crystals. For both forms, the elastic energy densities were similar, however significantly higher hysteretic losses were found for polycrystals. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Studies the influence of potassium comodification on the structure-property relationships of base ceramics. Potassium effects on various La-content compositions; Influence of field cooling on the structure-property relationships.

Deals with a study which investigated the amplitude-dependent complex piezoelectric response of relaxors using a single-beam interferometric technique as a function of alternating current electrical drive. Information on lead magnesium niobate; Methodology of the study; Results and discussion.

Details a study which examined the field-force antiferroelectric-to-ferroelectric phase transformation behavior of lead zirconate thin layers. Measurement of dielectric properties of lead zirconate; Experimental procedures; Characteristics of lead zirconate; Phase transformation of lead zirconate.

Presents a study which examined the dependence of the glasslike characteristics of lead scandium tantalate relaxor ferroelectrics on chemical ordering. Previous studies on relaxor behavior; Experimental procedure; Results and discussion.

The piezoelectric properties of ferroelectric and antiferroelectric thin layers were investigated by interferometry as a function of frequency and dc electric bias. Materials included: a ferroelectric lead zirconate titanate (PZT) with a Zr/Ti ratio of 53/47; a relaxor ferroelectric La-modified PZT with a Zr/Ti ratio of 70/30 and a La content of 7.8 at. %; and antiferroelectric lead zirconate. The hysteretic behavior of the piezoelectric coefficient due to polarization reversal was also studied. The layers were prepared by a sol-gel method, and were found to have properties similar to bulk ceramics. Significant strain levels could be achieved in the materials due to the relatively high electric strengths supported in thin-layer form. Polarization was found to be completely switchable between forward and reverse directions; however, the strain levels generated by switching were found to be inequivalent. In addition, pronounced piezoelectric relaxations and strong piezoelectric losses were observed. [ABSTRACT FROM AUTHOR]

Presents a study which applied a phenomenological model to explore the possible explanations of the inability of the microstructure in the lead magnesium niobate family of relaxor ferroelectrics to undergo continuous coarsening. Proposal regarding the excess free energy associated with the formation of the non-neutral phase; Application of the model to lanthanum-modified lead magnesium niobate; Balance of the gradient and electrostatic energy terms.

Deals with a study which investigated the temperature dependence of the complex refractive indices of sulfur iodide, molybdenium disulphide and BiVO[sub4] using spectroscopic ellipsometry. Background to the study; Experimental procedures; Results and discussions.

Presents a study which examined the structure-property relationships of lead zirconate titanate as a function of concentration of a lower-valent A-site substitution. Concentrations of higher-valent A-site substitutions; Properties of dielectric devices; Experimental results.

Presents a study which investigated the field-induced strain characteristics for a sequence of La-modified lead zirconate titanate (PLZT). Materials and methods used; Results of the study; Conclusions.

Deals with a study which observed double hysteresis loops in ferroelectric lead zirconate titanate ceramics. Information on the spontaneous polarization of ferroelectric crystals; Materials and experiments; Results and discussion.

Presents information on a study which investigated the dielectric properties of Sn-doped lead zirconate titanate ceramics for electromechanical transducers and actuators. Methodology of the study; Results and discussion; Conclusion.

The propagation of ion acoustic waves in plasmas composed of ions, positrons, and nonthermally distributed electrons is investigated. By means of the reduction perturbation technique, a nonlinear Schrödinger equation is derived and the modulation instability of ion acoustic wave is analyzed, where the nonthermal parameter is found to be of significant importance. Furthermore, analytical expressions for the bright and dark solitons are obtained, and the interaction of multiple solitons is discussed. [ABSTRACT FROM AUTHOR]

In this paper, first, the ETM is applied to obtain variable separation solutions of (2+1)-dimensional systems. A common formula with some arbitrary functions is derived to describe suitable physical quantities for some (2+1)-dimensional models such as the generalized Nizhnik-Novikov-Veselov, Davey-Stewartson, Broer-Kaup-Kupershmidt, Boiti-Leon-Pempinelli, integrable Kortweg-de Vries (KdV), breaking soliton and Burgers models. The universal formula in Tang, Lou, and Zhang [Phys. Rev. E 66, 046601 (2002)] can be simplified to the common formula in the present paper, which indicates that redundant process is included there since the easier variable separation form can be employed without loss of generality. Second, this method is successfully generalized to (1+1)-dimensional systems, such as coupled integrable dispersionless, long-wave–short-wave resonance interaction and negative KdV models, and obtain another common formula to describe suitable physical fields or potentials of these (1+1)-dimensional models, which is similar to the one in (2+1)-dimensional systems. Moreover, it also is extended to (3+1)-dimensional Burgers system, and find that the common formula in (2+1)-dimensional systems is also appropriate to describe the (3+1)-dimensional Burgers system. The only differences are that the function q is a solution of a constraint equation and p is an arbitrary function of three independent variables. Finally, based on the common formula for (2+1)-dimensional systems and by selecting appropriate multivalued functions, interactions among special dromion, special peakon and foldon are investigated. The interactions between two special dromions, and between two special peakons, both possess novel properties, that is, there exist a multivalued foldon in the process of their collision, which is different from the reported cases in previous literature. Furthermore, the explicit phase shifts for all the local excitations offered by the common formula have been given, and are applied to these novel interactions in detail. [ABSTRACT FROM AUTHOR]

A cylindrical Kadomstev-Petviashvili equation is derived in cylindrical geometry for dust acoustic waves in dusty plasmas consisting of positive ions, negative ions, and adiabatic variable charged dust grains. The effects of negative ions on the dust charge number and dust temperature, as well as the solitonic structures, such as the Nebulon and W-shape soliton, etc., have been investigated. It has also been found that the effect of transverse perturbations is the main factor that determines the formation of the Nebulon. [ABSTRACT FROM AUTHOR]

The dissipation caused by fluid viscosity is investigated for unmagnified dusty plasma with two-temperature ions in a spherical geometry. Analytical investigation shows that the propagation of a small-amplitude wave is governed by the spherical Kadomtsev-Petviashvili-Burgers equation. The shock wave solutions for dust-acoustic shock waves with two types of charged dust grains, that is, constant charged dust grains and adiabatic variable charged dust grains, are studied. The effects caused by dissipation and transverse perturbations are also discussed. [ABSTRACT FROM AUTHOR]

The effect of two-temperature nonthermal ions and variable dust charge on small-amplitude nonlinear dust-acoustic waves (DAW) is investigated. By using the reductive perturbation technique, the three-dimensional nonlinear Schrödinger equation (3D-NLSE) is first derived. The modulational instability of DAW in the magnetized dusty plasma is investigated as well. Meanwhile, some new and important stability regions are given. The effect of the nonthermal parameter a is shown to play a significant role in the determination of the normalized dust charge. Further, setting this parameter to zero degenerates the system into one in the magnetized dusty plasma consisting of the isothermal ions. [ABSTRACT FROM AUTHOR]

This article presents an acoustic method—the resonance acoustic field sensor or piezoelectric-sound-resonance cavity (PSRC)—for object position detection. This method utilizes the change of acoustic radiation impedance as a sensing mechanism. The PSRC both generates and detects a resonance acoustic field, along both the axial and transverse directions. We have discovered that an inserted object or an object motion in the sound radiation field results in changes in both the voltage and phase of the PSRC. Results have shown that a minimum object displacement of <10 μm can be detected in the axial direction (and <100 μm in the transverse) by this method. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The authors have found that the required dc magnetic bias of magnetoelectric (ME) laminates can be significantly altered, by incorporating additional high-permeability μ-metal layers. Investigations have focused on Tb1-xDyxFe2-y/Pb(Zr1-xTix)O3/μ-metal laminates. The authors’ results show that laminated μ-metal layers oriented perpendicular to an ac magnetic field concentrate flux in the composite, whereas those parallel to it attenuate flux. This results in (i) a significant decrease in the required dc magnetic bias Hdc, and (ii) an effective enhancement in the ME voltage coefficients at low Hdc, by a factor of up to 7.6. [ABSTRACT FROM AUTHOR]

A magnetoelectric (ME) laminate composite consisting of a symmetric longitudinally poled piezoelectric Pb(Mg1/3Nb2/3)O3–PbTiO3 crystal and two longitudinally magnetized magnetostrictive Tb1-xDyxFe2 layers has been developed that has a notably superior ME voltage coefficient, relative to previous laminate configurations. The symmetric nature of the longitudinally poled piezoelectric layer allows for operation in a push-pull mode that optimizes elastic coupling between layers. Our small laminate has a giant ME voltage coefficient of ∼1.6 V/Oe at low frequencies, a significant enhancement of this coefficient to ∼20 V/Oe under resonance drive, and an exceptional low-level magnetic field sensitivity of ∼10-12 T at f=f0. [ABSTRACT FROM AUTHOR]

A quasi-ring-type magnetoelectric (ME) laminate composite consisting of a circumferentially poled piezoelectric Pb(Zn1/3Nb2/3O)3-4.5 at. % PbTiO3single-crystal ring and two circumferentially magnetized magnetostrictive TERFENOL-D rings was fabricated and found to have a giant ME voltage coefficient of 2.2 V/Oe, or equivalently a ME field coefficient of 5.5 V/cm Oe, over the frequency range of 0.55 Hz. This circumferential-mode quasiring ME laminate can detect ac currents (noncontact) as small as 10-7 A, and/or a vortex magnetic field as small as 6×10-12 Tesla. In addition, we demonstrated current sensing capability of the quasiring laminate in a power electronics module. [ABSTRACT FROM AUTHOR]

A promising generation of extremely low frequency magnetic field sensors, based on multilayer composites (MLCs) of magnetostrictive Terfenol-D (Tb1-xDyxFe2-y) and piezoelectric Pb(Mg1/3Nb2/3)O3–PbTiO3, has been developed. Our MLC magnetoelectric sensor presently shows a limit in (i) working frequency of ∼5×10-3 Hz; and (ii) magnetic field sensitivity of 10-7, 10-9, and 10-11 T for frequencies of f=10-2, 1, and 102 Hz, respectively. The results open up possibilities for sensitive low frequency passive magnetic anomaly detection. [ABSTRACT FROM AUTHOR]

It has been found that ring-type magnetoelectric laminate composites of circumferentially magnetized magnetostrictive TERFENOL-D and a circumferentially poled piezoelectric Pb(Zr,Ti)O3 have high sensitivity to a vortex magnetic field. At room temperature, an induced output voltage from this ring laminate exhibited a near-linear response to an alternating current (ac) vortex magnetic field Hac over a wide magnetic field range of 10<9,Hac<10-3 T at frequencies between sub-Hz and kHz. [ABSTRACT FROM AUTHOR]

It has been found that a piezoelectrically driven sound-resonance cavity (PSRC) is quite sensitive to low-pressure changes: a change from ambient to vacuum (67 Pa) conditions results in a 89° phase shift and a -81% voltage decrease. Under vacuum conditions, the PSRC is highly sensitive (∼7 ppm) to leakage of H2 gas. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

It has been found that laminate composites of longitudinally magnetized magnetostrictive TERFENOL-D and a transversely poled piezoelectric Pb(Mg[sub 1/3]Nb[sub 2/3])O[sub 3]–PbTiO[sub 3] crystal have extremely high magnetic field sensitivity. At room temperature, an output voltage with an exceptionally good linear response to an ac magnetic field H[sub ac] was found over the range of 10[sup -11]

An acoustic position sensor, based on a piezoelectric-sound-resonance cavity (PSRC), is reported in which a resonance acoustic field is used as the sensing mechanism. It has been discovered that an inserted object or an object motion in the sound radiation field results in changes in the resonance state of the PSRC. Experiments have demonstrated a high position resolution in the axial direction, and also good sensitivity in the transverse. [ABSTRACT FROM AUTHOR]

Polarization reversal and domain dynamics have been investigated in 0.7Pb(Mg[sub 1/3]Nb[sub 2/3]) O[sub 3]–0.3PbTiO[sub 3] using a method of current transients. Investigations were performed as a function of applied electric field. The kinetics of the transients have been modeled to an equation of state for heterogeneous nucleation in the vicinity of random fields. Nucleation of polar clusters with a reversed polarization occurs under applied field in the vicinity of randomly quenched defects. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Examines the electrically induced phase transitions and decoupling of the induced strain and polarization in tin-modified lead zirconate titanate. Differences in the saturation behavior between the polarization and strain responses; Application of an electrical field in the antiferroelectric state; Observation on the polarization switching.

Examines the role of defect distributions and mobility on ferroelectric phase transformations in lead zirconate titanate films. Comparison between defects from temperatures above ferroelectric phase transformation and defects remaining mobile; Characterization of the normal ferroelectric state; Diffusion of chain fragments to domain boundaries.

We have found that laminates of longitudinally magnetized magnetostrictive TERFENOL-D layersand a longitudinally poled piezoelectric Pb(Mg1/3Nb2/3)O3-PbTiO3 crystal have a giant magnetoelectric voltage coefficient of >430 mV/Oe under a low magnetic bias. Under a resonant drive operation at a frequency of 82.1 kHz, the magnetoelectric coefficient was dramatically increased to ∼18.5 V/Oe. In addition, an ultrahigh magnetic field sensitivity of <10-11 T has been observed. [ABSTRACT FROM AUTHOR]

We deposited NaNbO3 (NNO)-Nb2O5 (NO) self-assembled heterostructures on LaAlO3 (LAO) to form ferroelectric-semiconductor vertically integrated nanostructures. The NNO component formed as nanorods embedded in a NO matrix. X-ray diffraction confirmed epitaxial growth of both NNO and NO phases. Phase distribution was detected by scanning electron microscopy. The NNO/NO volume ratio was strongly dependent on the deposition temperature due to the volatility of sodium. Piezoelectric force microscopy revealed a good piezoelectric response in the NNO component with a piezoelectric coefficient of D33 ≈ 12 pm/V, with SrRuO3 (SRO) acting as bottom electrode. The current-voltage characterization of NNO-NO/SRO-LAO showed a typical diode rectifying behavior. [ABSTRACT FROM AUTHOR]

The article presents a correction to the research paper "Three-dimensional nonlinear Schrödinger equation for dust-acoustic waves and its stability in magnetized dusty plasma with two-temperature nonthermal ions and dust charge variation," by Jie-Fang Zhang and Yue-yue Wang.