scholarly journals Structural and optical properties of a revived Pb0.5Ba1.5BiVO6 perovskite oxide

2019 ◽  
Vol 09 (01) ◽  
pp. 1950004 ◽  
Author(s):  
R. K. Parida ◽  
D. K. Pattanayak ◽  
Bhagyashree Mohanty ◽  
Nimai C. Nayak ◽  
B. N. Parida
Keyword(s):  
Perovskite Structure ◽  
Room Temperature ◽  
Microstructural Analysis ◽  
Compositional Analysis ◽  
Rhombohedral Phase ◽  
Double Perovskite ◽  
Xrd Analysis ◽  
Perovskite Oxide ◽  
Dielectric Study ◽  
Wide Range

The polycrystalline ceramic Pb[Formula: see text]Ba[Formula: see text]BiVO6 manifesting the complex double perovskite structure was tailored by the conventional solid state route at a moderate temperature. Qualitative phase analysis and formation of the ceramic were affirmed by XRD analysis. The X-ray powder diffraction pattern of the compound explored at room temperature affirms the single phase formation with double perovskite structure exhibiting rhombohedral phase. Microstructural analysis of the studied compound procured from the Scanning Electron Microscope (SEM) validates the formation of dense microstructures and nonuniformly distributed grains with minimal voids. Compositional analysis was shaped through the Electron Diffraction Spectroscopy (EDS) confirming the absence of contamination of any other metals apart from the mentioned ones. Dielectric (Cr and [Formula: see text]) parameters of the compound were studied using the LCR analyzer at different temperatures and wide range of frequencies. The polarization and dielectric study affirms the presence of ferroelectricity in the material with transition temperature much above the room temperature. The tangent dielectric loss of this sample being almost minimal at room temperature attributes it to find applications in different grounds of electronics. Optical equities of the ceramic were further analyzed by the RAMAN, FTIR, UV–Vis and Photoluminescence spectroscopy.

Dielectric Properties and Raman Spectroscopy in Ca-Substituted Na0.5Bi0.5TiO3 Ferroelectric Ceramics

2011 ◽  
Vol 324 ◽  
pp. 298-301 ◽  
Author(s):  
Roy Jean Roukos ◽  
Olivier Bidault ◽  
Julien Pansiot ◽  
Ludivine Minier ◽  
Lucien Saviot
Keyword(s):  
Raman Spectroscopy ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Rhombohedral Phase ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Ferroelectric Ceramics ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
X Ray

Lead free Na0.5Bi0.5TiO3 (NBT) and (Na0.5Bi0.5TiO3)1-x(CaTiO3)x (NBT-CT) piezoelectric ceramics with the perovskite structure were studied. The NBT and NBT-CT samples were synthesized using a solid-state reaction method and characterized with X-ray diffraction (XRD), Raman spectroscopy and dielectric measurements for several compositions (x = 0, 0.07, 0.15) at room temperature. The XRD analysis showed a stabilization of a rhombohedral phase at a low concentration of Ca (0 < x <0.15), whereas Raman spectra reveal a strong modification for the sample with x = 0.15. The dielectric properties of these ceramics were studied by measuring impedance in the 79-451K temperature range for unpoled and field cooling with an electric field (FC) conditions.

Effect of High Temperature Exposure on the Mechanical Properties of Self-Hardening Al-Based Alloy

2016 ◽  
Vol 879 ◽  
pp. 1489-1494
Author(s):  
Ildiko Peter ◽  
Christian Castella ◽  
Silvia Lombardo ◽  
Mario Rosso
Keyword(s):  
Room Temperature ◽  
Microstructural Analysis ◽  
Cost Effective ◽  
Structural Components ◽  
Grain Refiner ◽  
Casting Technique ◽  
Wide Range ◽  
Toughness Evaluation ◽  
Temperature Exposure ◽  
Mould Casting

Cost-effective, modified, self-hardening Al-based alloy is proposed for automotive and aircraft industries. AlZn10Si8Mg is produced by permanent mould casting technique, and the obtained material is re-melted to refine and modify its microstructure and to develop a mechanically more efficient alloy. Ti as grain refiner, in form of TiB, and modifier, in forms of AlSr, were added to the basic alloy composition. Microstructural analysis and impact toughness evaluation were performed at room temperature and up to 180°C. The results obtained confirm that the proposed alloy reveal good properties in the considered temperature range, and demonstrate their applicability for structural components development in the aforementioned areas and in a wide range of temperature.

scholarly journals Magnetic and Electrical Transport Properties of Double Perovskite Sr2FeMoO6Prepared by Sol-Gel Method

2011 ◽  
Vol 8 (s1) ◽  
pp. S189-S194 ◽  
Author(s):  
Yong-Qing Zhai ◽  
Jing Qiao ◽  
Zhang Zhang
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Room Temperature ◽  
Sol Gel ◽  
Double Perovskite ◽  
Reducing Agent ◽  
Perovskite Oxide ◽  
Electrical Transport Properties ◽  
Gel Method ◽  
Sol Gel Method

With activated carbon for reducing agent, the sol-gel method was used to prepare the giant magnetoresistance materials Sr2FeMoO6, which is the double Perovskite oxide. The structure, morphology, magnetic and electrical transport properties were investigated respectively by x-ray diffraction, scanning electron microscopy and vibrating sample magnetometer. The as-synthesized sample is Sr2FeMoO6with tetragonal crystal structure and I4/mmm space group and unit cell parameter is a = 5.580Å, c = 7.882Å. The primary particles are spherical in shape and the grain size is below 100 nm. The curie temperature is above room temperature and the saturation magnetization is 13.321 A·m2/kg under 1.0 T at room temperature. The sample exhibit typical semiconductor behavior and the conductive mechanism can be described by small polaron variable range hopping model. The room temperature magnetoresistance of the sample under 1.0 T field is up to -10.02%. Moreover, it is found the dosage of citric acid and the amount of reducing agent has great effect on the phase structure and magnetic properties of the samples.

Atomic-Scale Structure and Properties of Thin Epitaxial SrRuO3 Films Grown on SrTiO3 (100) by Pulsed Laser Deposition

1998 ◽  
Vol 541 ◽  
Author(s):  
K.M. Satyalakshmi ◽  
N. D. Zakharov ◽  
D. Hesse ◽  
G. Koren
Keyword(s):  
Pulsed Laser Deposition ◽  
Perovskite Structure ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Perovskite Oxide ◽  
Structural Defects ◽  
Ferromagnetic Transition ◽  
Structure And Properties ◽  
Wide Range ◽  
20 Nm

AbstractTransition metal oxides with perovskite structure exhibit a wide range of electrical properties. SrRuO3 (SRO), a perovskite oxide with high conductivity, finds applications as an electrode layer in ferroelectric devices and as a barrier layer in superconductor-normal metal-superconductor (SNS) Josephson junctions involving high Tc superconductors. Here we report on the structure and properties of thin SRO films on SrTiO3 (100) substrates grown by pulsed laser deposition. AFM investigations revealed that the SRO films exhibit island growth. The island size increases with thickness, and at a typical thickness of about 20 nm a connected network of islands is formed. The resistivity of the SRO films grown at different substrate temperatures (700 °C - 850 °C) exhibits metallic behavior with a ferromagnetic transition at 150 K. The films with typical thicknesses of 20 nm, grown at a substrate temperature of 775 °C exhibited the lowest resistivity of 200 μΩ-cm at 300 K, whereas the films grown at lower (700 °C) and higher (850 °C) temperatures showed a much higher resistivity at 300 K. By AFM and high resolution TEM investigations, this behavior is correlated with the atomicscale structure of the films. The film with the lowest room temperature resistivity showed an almost defect-free orthorhombic structure, whereas the film grown at 850 °C contained structural defects in high density, such as SrO-rich antiphase boundaries and twins located at the boundaries between the islands. The films grown at 700 °C showed a cubic perovskite structure, which is obviously the reason for their high resistivity.

High Piezoelectric Property and Low Dielectric Constant PZN-PZT Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 7-9 ◽  
Author(s):  
Dong Xiang Zhou ◽  
Yi Hua Deng ◽  
Shu Ping Gong ◽  
Bo Wu Yan ◽  
Zhi Qiang Zhuang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Tetragonal Phase ◽  
Perovskite Structure ◽  
Relative Dielectric Constant ◽  
Rhombohedral Phase ◽  
Xrd Analysis ◽  
Low Dielectric Constant ◽  
Pzt Ceramics ◽  
Low Dielectric ◽  
High Piezoelectric Property

The influences of the substitution of (Zn1/3Nb2/3) group for Ti as well as addition of Fe2O3 and K2CO3 on d33, kp, εr, and tgδ of the Pb[Zr0.46Ti0.54-x(Zn1/3Nb2/3)x]O3 + y mol%Fe2O3+z mol%K2CO3 (PZNPZT) (0 ≤ x ≤ 0.20, 0 ≤ y ≤ 0.10, 0 ≤ z ≤ 0.20) ceramics were investigated. The experimental results demonstrated that when x increases in Pb[Zr0.46Ti0.54-x(Zn1/3Nb2/3)x]O3+0.3 mol%Fe2O3+0.5mol%K2CO3 ceramics, the d33, kp, εr, and tgδ increase and approach to their maximum values, then eventually decrease. XRD analysis revealed that the perovskite structure of the materials transfers from tetragonal phase to rhombohedral phase. The relative dielectric constant (εr) decreases dramatically in the rhombohedral phase area near the MPB; the d33 and εr decrease with the small amount of added Fe2O3 and K2CO3, which also contributes to densification of the PZN-PZT ceramics. The optimized piezoelectric performances through the experiment were obtained as d33=280 pC/N, kp=0.62, εr=900, tgδ=0.003.

Room-temperature magnetoresistance in an oxide material with an ordered double-perovskite structure

Nature ◽  
10.1038/27167 ◽  
1998 ◽  
Vol 395 (6703) ◽  
pp. 677-680 ◽  
Author(s):  
K.-I. Kobayashi ◽  
T. Kimura ◽  
H. Sawada ◽  
K. Terakura ◽  
Y. Tokura
Keyword(s):  
Perovskite Structure ◽  
Room Temperature ◽  
Double Perovskite ◽  
Oxide Material

scholarly journals Combined experimental-theoretical study of electron mobility-limiting mechanisms in SrSnO3

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Tristan K. Truttmann ◽  
Jin-Jian Zhou ◽  
I-Te Lu ◽  
Anil Kumar Rajapitamahuni ◽  
Fengdeng Liu ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Room Temperature ◽  
Structural Disorder ◽  
Perovskite Oxide ◽  
Epitaxial Thin Films ◽  
Power Sources ◽  
Limited Mobility ◽  
Renewable Power ◽  
Wide Range ◽  
High Carrier Mobility

AbstractThe discovery and development of ultra-wide bandgap (UWBG) semiconductors is crucial to accelerate the adoption of renewable power sources. This necessitates an UWBG semiconductor that exhibits robust doping with high carrier mobility over a wide range of carrier concentrations. Here we demonstrate that epitaxial thin films of the perovskite oxide NdxSr1−xSnO3 (SSO) do exactly this. Nd is used as a donor to successfully modulate the carrier concentration over nearly two orders of magnitude, from 3.7 × 1018 cm−3 to 2.0 × 1020 cm−3. Despite being grown on lattice-mismatched substrates and thus having relatively high structural disorder, SSO films exhibited the highest room-temperature mobility, ~70 cm2 V−1 s−1, among all known UWBG semiconductors in the range of carrier concentrations studied. The phonon-limited mobility is calculated from first principles and supplemented with a model to treat ionized impurity and Kondo scattering. This produces excellent agreement with experiment over a wide range of temperatures and carrier concentrations, and predicts the room-temperature phonon-limited mobility to be 76–99 cm2 V−1 s−1 depending on carrier concentration. This work establishes a perovskite oxide as an emerging UWBG semiconductor candidate with potential for applications in power electronics.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

Dielectric study of primary amines from room temperature down to −180 °C and from 10 kHz up to 35 GHz

1999 ◽  
Vol 8 (3) ◽  
pp. 241-246
Author(s):  
J. M. Forniés-Marquina ◽  
A. Siblini ◽  
L. Jorat ◽  
G. Noyel
Keyword(s):  
Room Temperature ◽  
Primary Amines ◽  
Dielectric Study

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

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