Thermodynamics of (001) epitaxial ferroelectric films completely relaxed due to the formation of elastic domains with a three-domain architecture is presented. The polydomain structure and electromechanical response of such films are analyzed for two cases corresponding to immobile and mobile elastic domain walls. It is shown that immobile elastic domains provide additional constraint which increases the mechanical and electrical clamping, thereby significantly reducing the piezoelectric and ...

Ceramic powders of Na_1−xLi_xNbO₃ (LNN) have been synthesized by an aqueous sol–gel route. These solid solutions were prepared from Na–Li–Nb precursor gel. The precursor was synthesized from Na–EDTA, Li–EDTA and Nb–citrate complexes and they acted as the source of Na, Li and Nb, respectively. Citric acid and ethylenediaminetetraacetic acid (EDTA) were used as the chelating agents for Na, Li and Nb. The precursor gel was calcinated on a muffl...

ZrO₂ spherical nanometer powders containing 3.5 mol% Y₂O₃ have been prepared via the coupling route of water/oil (W/O) emulsion with dimethyl oxalate homogenous precipitation. ZrO₂ powders and their precursor powders have been characterized by XRD, TEM and SEM. According to the XRD result, phase volume fractions of powders were calculated by comparing the peaks’ intensities of spectrum. Furthermore, phase crystal lattice constants were obtained usin...

Manganese tetroxide (Mn₃O₄) nanofibers were prepared by electrospinning homogeneous viscous solution of 20?wt%, 28?wt% and 36?wt% manganese acetate in poly vinyl alcohol (PVA) and calcining the nanofibers at 1000?℃ for 2?h. Electrospinning was carried out at 9 kV DC with tip to collector distance (TCD) of 7?cm. Thermo gravimetric analysis (TGA) of the fibers indicates the pure phase of manganese oxide above 500?℃. XRD analysis of calcined (at 1000?℃)...

The perovskite-structure CdSnO₃ was obtained by calcinating CdSnO₃·3H₂O precursor at 550?℃, which was synthesized by hydrothermal process at 170?℃ for 16?h. The phase and microstructure of the obtained CdSnO₃ powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The CdSnO₃ powders exhibit uniformly cubic structure with side length of about 100?nm...

The effect of La³⁺ and Nd³⁺ on piezoelectric, dielectric and ferroelectric properties of PZT (Pb(Zr_0.53Ti_0.47)O₃) was studied. The powders were prepared by “wet-chemical” route followed by calcination at 800?℃ for 4?h. XRD analysis of the calcined powders confirms the tetragonal phase in the undoped PZT, which gradually decreases with the dopant concentration and the appearance of rhombohedral phase simultaneously. SEM study of sin...

A misfit layer sulfide (BiS)_1.2(TiS₂)₂ with a natural superlattice structure has been shown to be a promising thermoelectric material, but its high carrier concentration should be reduced so as to further optimize the thermoelectric performance. However, ordinary acceptor doping has not succeeded because of the non-parabolic band structure. In this paper, we have successfully doped chromium ions into the Ti sites, which can maintain or even enhance the high ef...

The effects of cerium substitution, use of additives, and heating temperature on the chemical composition and catalytic activity of iron phosphate were evaluated. Iron–cerium phosphate was prepared from iron nitrate, ammonium cerium nitrate, and sodium phosphate in ethylene glycol using sodium dodecyl-sulfate or acetylacetone as additive. The chemical composition, particle shape and size distribution of the obtained samples were respectively evaluated based on ICP and XRD, SEM, and laser diff...

Yttria-stabilized zirconia (YSZ, ZrO₂–8%Y₂O₃) films were deposited onto lanthanum strontium manganite (LSM, La_0.7Sr_0.3MnO₃) substrates using dip-coating process aiming for the application in solid oxide fuel cells (SOFCs). YSZ precursor was prepared by sol–gel method; three values of the organic/inorganic concentration ratio (1, 3 and 5) were utilized and the sol viscosity was adjusted (60?mPa·s and 100?mPa·s) before deposition...

Hydroxyapatite–magnesium titanate composite nanopowders have been developed using a mechanothermal process. Thermal treatment of the milled powders at 700?℃ resulted in the formation of HAp/MgTiO₃–MgO nanocomposite. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX) techniques were utilized to characterize the synthesized powders. The results revealed that the dominant phases aft...

Magnesium aluminum silicate (MgO–Al₂O₃–SiO₂, MAS) glass-ceramic was prepared via sintering route. X-ray diffraction (XRD) analysis indicates the formation of multiphase compound with magnesium silicate fluoride and cordierite as major phases. Dielectric studies of the compound shows a strong frequency dispersion of permittivity in the low frequency region followed by a nearly frequency-independent behavior in the high frequency region. The presence of alkali i...

This paper presents the findings on thermal expansion behavior of slaked lime doped rice husk silica (RHS) refractory monitored between 25?℃ and 1500?℃. It also reports the phase transition analysis within the temperature range of 850–1450?℃. A sudden expansion of 0.7% noticed at 220?℃ is due to the transformation of α-cristobalite to β-cristobalite. The highest expansion (0.85%) reached within the temperature range of 650–850?℃, remains almost...

In this article, a new method has been presented for the estimation of fracture toughness in brittle materials, which enjoys improved accuracy and reduced costs associated with fracture toughness testing procedure compared to similar previous methods, because a vast range of specimens with irregular cracks can be accommodated for testing. Micron-sized alumina powders containing 0.05 wt% magnesium oxide (MgO) nanoparticles were mixed and also together with 2.5 vol%, 5 vol%, 7.5 vol%, 10 vol%, ...