Volume Fraction Of BaTiO3 Research Articles

Analytical solutions for nonlinear magneto-electro-elastic vibration of smart sandwich plate with carbon nanotube reinforced nanocomposite core in hygrothermal environment

This paper presents an analytical approach on the nonlinear magneto-electro-elastic vibration of smart sandwich plate. The sandwich plate consists of a carbon nanotube reinforced nanocomposite (CNTRC) core integrated with two magneto-electro-elastic face sheets. For core layer, three types of carbon nanotube (CNT) distribution such as FG-O, FG-V, FG-X are considered while the volume fraction of BaTiO3 − CoFe2O4 in each face sheet is chosen to be 0.5. It is assumed that the smart sandwich plate is rested on Pasternak-type elastic foundations and subjected to the combination of external pressure, thermal, electric and magnetic loads. The coupled constitutive relations are derived based on the Hamilton's principle in which the kinematic nonlinearity is defined using Reddy's higher order shear deformation theory. The analytical solutions which satisfy the boundary conditions are assumed to have the trigonometric form. The Galerkin method is used to obtain the closed form expressions of natural frequency, the relation between the frequency ratio and dimensionless amplitude and the dynamic response of the sandwich plate. The numerical results are conducted to illustrate the effect of geometrical parameters, CNT volume fraction, temperature and moisture increment, electric and magnetic potentials on the nonlinear vibration of smart sandwich plate. The reliability of present results is evaluated by comparing with the previous results based on different approach.

Effect of arrangement of nano and micro barium titanate (BaTiO3) particles on the enhanced dielectric constant of high‐density polyethylene (HDPE)/BaTiO3

ABSTRACTThe aim of this study is to improve the dielectric and mechanical properties of HDPE/BaTiO3 composites by binary BaTiO3 particles, when the volume fraction of BaTiO3 is constant. In this study, it was found that the pack density of binary BaTiO3 particles in HDPE/BaTiO3 composite relies on particle ratio and volume fraction of small particles. It is found that the addition of 50 vol % 1600 nm BaTiO3 particles can boost the dielectric constant of HDPE control from 2 to 30 (14 times higher) at 40 Hz and 19 (8.5 times higher) at 40 MHz, respectively. When the particle ratio was 4, the substitution of 10 vol % 1600 nm BaTiO3 particles by 10 vol % 400 nm BaTiO3 particles can further enhance the dielectric constant of HDPE/L‐BT (10/10) from 30 to 50 (67% increase) at 40 Hz and from 19 to 42 (121% increase) at 40 MHz, respectively, without greatly influencing the volume resistivity of HDPE composites. In addition, the thermal conductivity of HDPE with binary BaTiO3 particles were all above 2.0 W/(m•K). © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 1101–1108

Preparation and properties of Barium titanate (BaTiO3) reinforced high density polyethylene (HDPE) composites for electronic application

In this study, 3-Aminopropyltriethoxysilane (KH550) with polar amino groups is applied to modify the surface of Barium titanate (BaTiO3) particles. When volume fraction of BaTiO3 further increases to 50 vol%, the dielectric constant and loss of HDPE control increase from 2.5 and 0.02 to 18.5 and 0.10 at 10 MHz, respectively, with the volume resistivity of HDPE control decreasing from 3.6 × 1013 Ω m to 3.5 × 1011 Ω m. The increased amount of modified BaTiO3 can increase the flexural strength and modulus HDPE composites from 8 and 90 MPa to 14 and 780 MPa, respectively. However, the increase of modified BaTiO3 can restrict mobility of HDPE chains and decrease the crystallinity of HDPE composites.

Preparation of BaTiO<sub>3</sub>/PMMA Dielectric Films by Screen Printing

The high-k composite dielectric ink is prepared by dispersing the surface modified BaTiO3 in PMMA solution. The high quality BaTiO3-PMMA composite films are screen printed on ITO glasses. BaTiO3 nanoparticles are surface modified with a silane coupling agent (MPTMS) to improve their affinity for PMMA matrix. The dielectric constant, loss tangent, specific capacitance and transmittance of BaTiO3/PMMA nanocomposites are investigated as the function of volume fraction of BaTiO3. These composites, which possess both high dielectric constant and low dissipation factors and can be screen printed at ambient temperature and pressures, have very wide practical applications.

Magnetic Behaviors of BaTiO<sub>3</sub>-BaFe<sub>12</sub>O<sub>19</sub> Nanocomposite Prepared by Sol-Gel Process Based on Differences in Volume Fraction

Barium titanate BaTiO3 (BTO) - barium hexaferrite BaFe12O19 (BHF) nanocomposite could be as a raw material of multiferroic. Multiferroic is a class of materials with coupled electric, magnetic and structural order parameters that yield simultaneous effects of ferroelectric, ferromagnetism and ferroelasticity in the same material. This material has potential applications in such as spintronic devices and sensors. This work was an earlier research towards formation of multiferroic material. Knowing magnetic properties that will lead to a better understanding of magnetoelectric coupling in multiferroic material is the objective of this research.The samples were BTO and BHF prepared by sol-gel and then were mixed in bulk system by a conventional techniques in various of volume fraction between BTO : BHF = 1:1 ; 1:2 and 2:1, then samples were sintered at 925°C for 5, 10 and 15 hours. Composite phase study was carried out using X-Ray Diffraction (XRD). MPS Magnet Physik EP3 Permagraph L was used to characterize magnetic properties. XRD results confirm that composite with volume fraction of BTO : BHF = 1:1 with sintering at 925°C for 5 hours consists only of 2 phases BTO and BHF. There is impurity phase BaFe2O4 beside BTO and BHF phases at samples with volume fraction BTO:BHF = 1:2 and 2:1 for longer sintering. Composite with volume fraction of BTO:BHF = 1:1 for 5 hours sintering has a high value of remanent magnetization 0.081 T and the lowest value of intrinsic coersive 333.6 kA/m leading to good characteristics of multiferroic materials.

Magnetic Behaviors of BaTiO<sub>3</sub>-BaFe<sub>12</sub>O<sub>19</sub> Nanocomposite Prepared by Sol-Gel Process Based on Differences in Volume Fraction

Barium titanate BaTiO3 (BTO) - barium hexaferrite BaFe12O19 (BHF) nanocomposite could be as a raw material of multiferroic. Multiferroic is a class of materials with coupled electric, magnetic and structural order parameters that yield simultaneous effects of ferroelectric, ferromagnetism and ferroelasticity in the same material. This material has potential applications in such as spintronic devices and sensors. This work was an earlier research towards formation of multiferroic material. Knowing magnetic properties that will lead to a better understanding of magnetoelectric coupling in multiferroic material is the objective of this research.The samples were BTO and BHF prepared by sol-gel and then were mixed in bulk system by a conventional techniques in various of volume fraction between BTO : BHF = 1:1 ; 1:2 and 2:1, then samples were sintered at 925°C for 5, 10 and 15 hours. Composite phase study was carried out using X-Ray Diffraction (XRD). MPS Magnet Physik EP3 Permagraph L was used to characterize magnetic properties. XRD results confirm that composite with volume fraction of BTO : BHF = 1:1 with sintering at 925°C for 5 hours consists only of 2 phases BTO and BHF. There is impurity phase BaFe2O4 beside BTO and BHF phases at samples with volume fraction BTO:BHF = 1:2 and 2:1 for longer sintering. Composite with volume fraction of BTO:BHF = 1:1 for 5 hours sintering has a high value of remanent magnetization 0.081 T and the lowest value of intrinsic coersive 333.6 kA/m leading to good characteristics of multiferroic materials.

Phase Diagrams of BaTiO3/BaZrO3 Superlattices

Temperature-misfit strain phase diagrams of BaTiO3/BaZrO3 superlattices were developed and an alteration of the “misfit strain-temperature” phase diagrams against the changing of ferroelectric layers volume fraction was investigated. The topology of developed phase diagrams is similar to that of single BaTiO3 film, but phase transition lines exhibit substation shifts. According to our approach, the main reason of this shift is the electrostatic interaction between the layers. It is revealed that only one polar phase remains stable in superlattices with volume fraction of BaTiO3 being less than 70%.

Piezoelectric and dielectric properties of siloxane elastomers filled with bariumtitanate

Piezoelectric elastomers were prepared from suspensions of bariumtitanate (BaTiO3) particles in a telechelic polydimethylsiloxane (t-PDMS) by crosslinking the t-PDMS under an electric field. Crosslinking reaction was monitored by measurement of complex dielectric constant ε′ − iε″. Dielectric constant ε′ increased with increasing BaTiO3 content, and agreed approximately with the theoretical ε′ calculated with the Maxwell–Wagner theory. Piezoelectric constant d33 of the poled elastomers was measured by application of compressions in the direction of the poling field. It was found that d33 was of the order of 10−11 C/N and increased steeply with increasing content of BaTiO3 but became almost independent of composition in the range of BaTiO3 content from 3 to 14 vol %. To examine the effect of electric field on the aggregation structure of the particles, we observed light scattering of the suspension under an electric field, and found that the scattering pattern became anisotropic. This indicated that the particles are connected like a pearl necklace and are stretched in the direction of the poling field. The dependence of d33 on the volume fraction of BaTiO3 was explained by a model proposed by Banno. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 3065–3070, 1999

Effective Dielectric Constant of BaTiO3-PVDF Systems

Effective dielectric constant of heterogeneous layers, in which BaTiO3 particles are dispersed in PVDF matrix, has been studied experimentally. Two kinds of samples, fused and cast BaTiO3-PVDF layers, were prepared for dielectric measurements. When the values of effective dielectric constant for the BaTiO3-PVDF layers were plotted against the volume fraction of BaTiO3, it was found that the experimental values were inside of the Hashin-Shtrikman bounds and fitted to the van Beek theory for both the fused and cast samples. However, the values of the shape factor D in the theory were different with each other for the fused and the cast samples, suggesting a difference in the phase distribution between the two samples.