Temperature-dependent volume fraction of polar nanoregions in lead-free (1−x)(Bi0.5Na0.5)TiO3−xBaTiO3 ceramics

2017 ◽  
Vol 95 (2) ◽  
Author(s):  
M. Vögler ◽  
N. Novak ◽  
F. H. Schader ◽  
J. Rödel
Keyword(s):  
Volume Fraction ◽  
Lead Free ◽  
Temperature Dependent ◽  
Polar Nanoregions

Temperature dependent fracture toughness of KNN-based lead-free piezoelectric ceramics

2019 ◽  
Vol 174 ◽  
pp. 369-378 ◽  
Author(s):  
Yingwei Li ◽  
Yixuan Liu ◽  
Paul-Erich Öchsner ◽  
Daniel Isaia ◽  
Yichi Zhang ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Temperature Dependent

Dielectric Behavior of Mechano-chemically Synthesized [(CH3NH3)3Bi2Br9]: A Lead Free Hybrid Perovskite

2021 ◽  
Author(s):  
Swagatalaxmi Pujaru ◽  
Priyabrata Sadhukhan ◽  
Basudev Ghosh ◽  
Arup Dhara ◽  
Sachindranath Das
Keyword(s):  
Impedance Spectroscopy ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Dielectric Behavior ◽  
Lead Free ◽  
Published Data ◽  
Temperature Dependent ◽  
Microstructural Parameters ◽  
Hybrid Perovskite ◽  
Refinement Method

Abstract Lead free hybrid halide perovskite (CH3NH3)3Bi2Br9 has been successfully synthesized by mechano-chemical method. The microstructure analysis by Rietveld’s refinement method revealed that the crystal belongs to trigonal system with space group P3 ̅m1. The obtained microstructural parameters are well in agreement with the previously published data. Temperature-dependent ac conductivity, impedance spectroscopy, and complex dielectric properties have been investigated in detail. The negative temperature coefficient of resistance behaviour reveals the semiconducting nature of the materials. The complex impedance spectroscopy also supports the semiconducting nature of the sample with activation energy for conduction ~0.38 eV.

scholarly journals Comparative study on the performance of piezo-active 1–3-type composites with lead-free components

2021 ◽  
pp. 2160003
Author(s):  
Ashura N. Isaeva ◽  
Vitaly Yu. Topolov
Keyword(s):  
Single Crystal ◽  
Piezoelectric Coefficient ◽  
Piezoelectric Properties ◽  
Volume Fraction ◽  
Lead Free ◽  
Figures Of Merit ◽  
Piezoelectric Energy ◽  
Harvesting Systems ◽  
Porous Matrices ◽  
Large Anisotropy

Piezoelectric properties and related figures of merit are studied in novel 1–3-type composites based on ferroelectric domain-engineered lead-free single crystal with the relatively large longitudinal piezoelectric coefficient [Formula: see text]. Relationships between the piezoelectric properties and the set of figures of merit are analyzed for the 1–3 and 1–3–0 composites that contain the same single-crystal and polymer components. For a composite characterized by 1–3–0 connectivity, an influence of a porous piezo-passive matrix on the figures of merit and their volume-fraction behavior is considered additionally. A large anisotropy of figures of merit is observed in the 1–3–0 composite with specific porous matrices. A diagram is put forward to show volume-fraction regions of the large anisotropy of figures of merit of the studied 1–3–0 composite. Due to large figures of merit and their considerable anisotropy, the studied lead-free composites can be applied in piezoelectric energy-harvesting systems, sensors, transducers, and so on.

scholarly journals Effects of Second-Order Slip Flow and Variable Viscosity on Natural Convection Flow of CNTs − Fe 3 O 4 /Water Hybrid Nanofluids due to Stretching Surface

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Ayele Tulu ◽  
Wubshet Ibrahim
Keyword(s):  
Volume Fraction ◽  
Local Heat Transfer ◽  
Velocity Slip ◽  
Local Heat ◽  
Second Order ◽  
Hybrid Nanoparticles ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Hybrid Nanofluids ◽  
Dependent Viscosity

This study deals with natural convection unsteady flow of CNTs − Fe 3 O 4 /water hybrid nanofluids due to stretching surface embedded in a porous medium. Both hybrid nanoparticles of SWCNTs − Fe 3 O 4 and MWCNTs − Fe 3 O 4 are used with water as base fluid. Effects of hybrid nanoparticles volume friction, second-order velocity slip condition, and temperature-dependent viscosity are investigated. The governing problem of flow is solved numerically employing spectral quasilinearization method (SQLM). The results are presented and discussed via embedded parameters using graphs and tables. The results disclose that the thermal conductivity of CNTs − Fe 3 O 4 / H 2 O hybrid nanofluids is higher than that of CNTs − H 2 O nanofluids with higher value of hybrid nanoparticle volume fraction. Also, the results show that momentum boundary layer reduces while the thermal boundary layer gros with higher values of temperature-dependent viscosity and second-order velocity slip parameters. The skin friction coefficient improves, and the local heat transfer rate decreases with higher values of nanoparticle volume fraction, temperature-dependent viscosity, and second-order velocity slip parameters. Furthermore, more skin friction coefficients and lower local heat transfer rate are reported in the CNTs − Fe 3 O 4 / H 2 O hybrid nanofluid than in the CNTs − H 2 O nanofluid. Thus, the obtained results are promising for the application of hybrid nanofluids in the nanotechnology and biomedicine sectors.

scholarly journals Nano-domains in lead-free piezoceramics: a review

2020 ◽  
Vol 8 (20) ◽  
pp. 10026-10073 ◽  
Author(s):  
Xiang Lv ◽  
Xi-xiang Zhang ◽  
Jiagang Wu
Keyword(s):  
Systematic Review ◽  
Lead Free ◽  
Polar Nanoregions

A systematic review summarizing and analyzing the role of recently observed nano-domains and polar nanoregions (PNRs) in lead-free piezoceramics.

Temperature‐dependent fatigue modelling of a novel Ni, Bi and Sb containing Sn‐3.8Ag‐0.7Cu lead‐free solder alloy

2020 ◽  
Vol 43 (12) ◽  
pp. 2883-2891
Author(s):  
Q.B. Tao ◽  
L. Benabou ◽  
Van Nhat Le ◽  
Ngoc Anh Thi Nguyen ◽  
Hung Nguyen‐Xuan
Keyword(s):  
Solder Alloy ◽  
Lead Free ◽  
Lead Free Solder ◽  
Temperature Dependent ◽  
Lead Free Solder Alloy ◽  
Free Solder

Designing Optimal Volume Fractions For Functionally Graded Materials With Temperature-Dependent Material Properties

2006 ◽  
Vol 74 (5) ◽  
pp. 861-874 ◽  
Author(s):  
Florin Bobaru
Keyword(s):  
Functionally Graded Materials ◽  
Material Properties ◽  
Volume Fraction ◽  
Effective Properties ◽  
Functionally Graded ◽  
Dominant Factor ◽  
Temperature Dependent ◽  
Graded Materials ◽  
Critical Stresses ◽  
Non Linear

We present a numerical approach for material optimization of metal-ceramic functionally graded materials (FGMs) with temperature-dependent material properties. We solve the non-linear heterogeneous thermoelasticity equations in 2D under plane strain conditions and consider examples in which the material composition varies along the radial direction of a hollow cylinder under thermomechanical loading. A space of shape-preserving splines is used to search for the optimal volume fraction function which minimizes stresses or minimizes mass under stress constraints. The control points (design variables) that define the volume fraction spline function are independent of the grid used in the numerical solution of the thermoelastic problem. We introduce new temperature-dependent objective functions and constraints. The rule of mixture and the modified Mori-Tanaka with the fuzzy inference scheme are used to compute effective properties for the material mixtures. The different micromechanics models lead to optimal solutions that are similar qualitatively. To compute the temperature-dependent critical stresses for the mixture, we use, for lack of experimental data, the rule-of-mixture. When a scalar stress measure is minimized, we obtain optimal volume fraction functions that feature multiple graded regions alternating with non-graded layers, or even non-monotonic profiles. The dominant factor for the existence of such local minimizers is the non-linear dependence of the critical stresses of the ceramic component on temperature. These results show that, in certain cases, using power-law type functions to represent the material gradation in FGMs is too restrictive.

scholarly journals Structure and temperature dependent electrical properties of lead-free Bi0.5Na0.5TiO3- SrZrO3ceramics

2014 ◽  
Vol 60 ◽  
pp. 012047 ◽  
Author(s):  
Adnan Maqbool ◽  
Jamil ur Rahman ◽  
Ali Hussain ◽  
Jong Kyu Park ◽  
Tae Gone Park ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Lead Free ◽  
Temperature Dependent

The Temperature Dependence of the Viscosity of Suspensions of Polystyrene Latices in LiCl Solutions

1981 ◽  
Vol 36 (4) ◽  
pp. 329-331
Author(s):  
A. Bonincontro ◽  
C. Cametti ◽  
A. Di Biasio
Keyword(s):  
Temperature Dependence ◽  
Volume Fraction ◽  
Temperature Dependent

The viscosities of suspensions of polystyrene particles in aqueous LiCl solutions (about 3.5 · 10-4 M) at temperatures from 0 to 60 °C were measured and fitted to relations of the form η = η0(1+K1ϕ+K2ϕ2)i where ϕ is the volume fraction of the particles.In contradiction to existing theories the coefficients K1 and K2 were found to be temperature dependent

Crosswise stream of methanol–iron oxide (CH3OH–Fe3O4) with temperature-dependent viscosity and suction/injection effects

2019 ◽  
Vol 233 (5) ◽  
pp. 1013-1023 ◽  
Author(s):  
Rabil Tabassum ◽  
R Mehmood
Keyword(s):  
Heat Transfer ◽  
Volume Fraction ◽  
Treatment Plant ◽  
Exponential Model ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Coating Materials ◽  
Similarity Transformations ◽  
Dependent Viscosity ◽  
Energy Equations

Manufacturing of modern coating materials doped with magnetic nanoparticles has arisen as an exciting new area of materials processing fluid dynamics. Methanol is primarily used in chemical manufacturing, specialized vehicles fuel, energy carrier, as an antifreeze in pipelines, in wastewater treatment plant, and many more. In this article, a mathematical model is therefore developed to study crosswise flow of methanol-based ferromagnetic fluid through a permeable medium with suction/injection effects. Temperature-dependent viscosity is taken with Reynolds exponential model. The Tiwari–Das and Maxwell–Garnett nanofluid models are used, which alters the electrical conductivity, density, and thermal conductivity properties with nanoparticle volume fraction. The two-dimensional mass, momentum, and energy equations are normalized into nonlinear system comprising ordinary differential equations via appropriate similarity transformations. The solution of the emerging physical problem is attained by shooting scheme in MATLAB symbolic software. Validation of the results is presented through comparison with previously reported literature in the limiting sense. The influence of pertinent parameters on the flow and heat transfer characteristics is revealed through graphs. It is found that velocity profiles are suppressed with greater magnetic parameter and porosity parameters but temperature profile is enhanced. Velocity and temperature profiles for injection case are higher when compared with the suction phenomenon. Shear stress at the wall is decreased with volume fraction. Heat transfer gradient at the wall is significantly enhanced with volume fraction.

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