scholarly journals Ferroelectric and Magnetic Properties of Hot-Pressed BiFeO3-PVDF Composite Films

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Annapu V. Reddy ◽  
K. C. Sekhar ◽  
Navneet Dabra ◽  
A. Nautiyal ◽  
Jasbir S. Hundal ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Coercive Field ◽  
Polyvinylidene Fluoride ◽  
Room Temperature ◽  
Magnetic Hysteresis ◽  
Composite Films ◽  
Hysteresis Loops ◽  
Liquid Phase Sintering ◽  
Magnetic Hysteresis Loops ◽  
Ferroelectric Hysteresis

The ferroelectric and magnetic properties of hot-pressed BiFeO3- (BFO) polyvinylidene fluoride (PVDF) composite films have been studied. The BiFeO3 (BFO) ceramics have been synthesized by a rapid liquid phase sintering technique. The X-ray diffraction (XRD) studies revealed that the impure phase observed in pure BFO ceramics was significantly reduced in the composite films. The presence of both ferroelectric and magnetic hysteresis loops confirms the multiferroic nature of the composite films at room temperature. A well-saturated ferroelectric hysteresis loop with a remanent polarization (Pr)∼4.8 μC-cm-2 and coercive field (Ec)∼1.55 kV/cm has been observed in composite thin films at room temperature. The magnetic hysteresis loops were traced at room temperature with SQUID. The remanent magnetization (Mr)∼3.0×10−3 emu/gm and coercive field (Hc)∼0.99 kOe was observed in the composite film. The magnetic polarization of the composite films has found to be enhanced as compared to pure BFO and correlated to reduction in BFO impure peak intensity.

Dielectric and magnetic properties in Ta-substituted BiFeO3 ceramics

2007 ◽  
Vol 22 (12) ◽  
pp. 3397-3403 ◽  
Author(s):  
Youn-Ki Jun ◽  
Sung Bo Lee ◽  
Miyoung Kim ◽  
Seong-Hyeon Hong ◽  
Jae Wook Kim ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
High Resistivity ◽  
Magnetic Dipoles ◽  
Low Dielectric ◽  
Polycrystalline Ceramics ◽  
Magnetic Hysteresis Loops

The dielectric and magnetic properties were investigated in Ta-substituted BiFeO3 polycrystalline ceramics synthesized by a solid-state reaction. The Ta substitution decreased the grain size by two orders of magnitude compared with that of unsubstituted ceramics and increased the electrical resistivity by 6 orders of magnitude. The high resistivity and low dielectric loss allowed the dielectric constant to be determined at room temperature. The magnetic hysteresis loops were observed in the Ta-substituted BiFeO3, and the appearance of ferromagnetism was closely associated with the distortion of the oxygen octahedra by the Ta substitution. The coupling between the electric and magnetic dipoles was examined by determining the changes of the dielectric constant with the external magnetic field.

MAGNETIC PROPERTIES OF THE HIGH Tc SUPERCONDUCTORS BiSrCaCuO AND TlBaCaCuO

1989 ◽  
Vol 03 (01) ◽  
pp. 77-85 ◽  
Author(s):  
Y. D. DAI ◽  
C. LIN ◽  
W. B. ZHANG ◽  
S. Q. FENG ◽  
X. ZHU ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Flux Pinning ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
High Tc Superconductors ◽  
Magnetic Current ◽  
High Tc ◽  
Bean Model ◽  
Current Densities ◽  
Magnetic Hysteresis Loops

Magnetic properties of the high T c superconductors BiSrCaCuO and TlBaCaCuO were investigated systematically. Magnetic current densities were calculated from magnetic hysteresis loops of bulk and powdered samples by Bean model. The results showed that flux pinning in these materials is much weaker than that in YBaCuO.

The Influence of CeO2-Doping of Nanosized Cadmium Ferrite on Catalytic Conversion of Ethanol

2020 ◽  
Vol 13 (2) ◽  
pp. 156-169
Author(s):  
Abdelrahman A. Badawy ◽  
Ahmed M. Rashad ◽  
Shaimaa M. Ibrahim ◽  
Sahar M. El-Khouly
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Magnetic Hysteresis ◽  
Maximum Yield ◽  
Hysteresis Loops ◽  
Ethanol Conversion ◽  
Ferrite Formation ◽  
Opposite Trend ◽  
Magnetic Hysteresis Loops

Background: The role of CeO2-doping (0.75-3 mol%) and calcination temperature on solid-solid interaction between ferric and cadmium oxides yielding cadmium ferrites was examined. Methods and Results: The results exposed that ceria improves the ferrite formation by heating at 600-700ºC via the dissolution of some dopant cation in the lattice of CdO with the subsequent creation of anionic vacancies and/or formation of higher valency cadmium cation (Cd(2+δ)+). SBET of solids calcined at 500oC increased by CeO2-doping, while opposite trend for solids calcined at 600 and 700oC. The magnetic hysteresis loops of all samples showed room-temperature ferromagnetism with different hysteresis loop shapes. Conclusion: Magnetization increased by CeO2-doping that might be due to the enhancement of cadmium ferrite formation. Ethanol conversion increased by increasing CeO2-doping. Dehydrogenation product (acetaldehyde) was mainly the yield of ethanol conversion. The maximum yield of acetaldehyde (92.97%) carried out for solids doped with 3 mol% CeO2.

Structural and Magnetic Properties of the Rapid Cooled Alloys: Fe60Co10Y5+xZr5-xB20 (Where: x = 0 or 2)

2019 ◽  
Vol 70 (1) ◽  
pp. 224-227
Author(s):  
Marcin Nabialek ◽  
Bartlomiej Jez ◽  
Kinga Jez ◽  
Katarzyna Bloch
Keyword(s):  
Room Temperature ◽  
Nanocrystalline Material ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Single Step ◽  
Magnetic Polarization ◽  
X Ray ◽  
High Temperature Alloys ◽  
Magnetic Hysteresis Loops ◽  
Vibration Magnetometer

This article presents the results of tests on high-temperature alloys, produced on the basis of the FeCoB matrix. The nanocrystalline material was produced in a single-step process of rapid cooling of liquid alloy that was injected into a copper mould. Alloy samples were obtained in the form of 10mm x 5mm x 0.5mm tiles. Studies of the structure of the manufactured alloys were undertaken using Bruker X-ray analysis equipment (featuring a CuKa lamp). The magnetic polarization of saturation was measured, as a function of temperature, using a Faraday magnetic balance; the measurements ranged from room temperature up to 850K. Through numerical analysis of the curves, the Curie temperature of the investigated alloys was determined. Using a vibration magnetometer, static magnetic hysteresis loops were measured. The magnetization of saturation of the tested alloys was greater than 1 T, while the coercive field values were 400 and 16600 A/m. The stiffness parameter of the spin wave Dspf was determined.

Magnetic properties of a tri-decorated graphene structure: Monte Carlo study

2016 ◽  
Vol 30 (32) ◽  
pp. 1650233
Author(s):  
A. Jabar ◽  
N. Tahiri ◽  
L. Bahmad ◽  
A. Benyoussef
Keyword(s):  
Monte Carlo ◽  
Magnetic Properties ◽  
Phase Diagrams ◽  
Ground State ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Monte Carlo Study ◽  
Magnetic Hysteresis Loops ◽  
Reduced Temperature ◽  
Good Agreement

In this paper, we study the magnetic properties of a tri-decorated [Formula: see text] graphene structure using Monte Carlo simulations (MCS). Indeed, we first elaborate the ground state phase diagrams and then, we found that from [Formula: see text] phases, the only stable configurations are: [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]. For low reduced temperature values, the partial magnetizations are found to be in good agreement with the corresponding ground state phase diagrams. The corresponding partial susceptibilities show a notable peak around the reduced temperature value 2.0 in the absence of the external magnetic field [Formula: see text] and crystal field [Formula: see text]. To complete this study, we present and discuss the magnetic hysteresis loops.

Room Temperature Magnetoelectric Coupling in Bi5Ti3FeO15 Ceramics

2013 ◽  
Vol 668 ◽  
pp. 762-766 ◽  
Author(s):  
X.Q. Chen ◽  
Xiang Bin Zeng ◽  
F.J. Yang ◽  
X.P. Kong ◽  
C. Wei ◽  
...  
Keyword(s):  
Electric Field ◽  
Room Temperature ◽  
Magnetic Measurement ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Solid State Reaction Method ◽  
Layered Perovskite ◽  
Conventional Solid State Reaction ◽  
Magnetic Dipoles ◽  
Ferroelectric Hysteresis

Magnetoelectric(ME) coupling at room temperature(RT) in four-layered perovskite Bi5Ti3FeO15(BTFO) ceramics prepared by conventional solid state reaction method was observed. Unsaturated ferroelectric hysteresis loop with 2Pr=0.464 μC/cm2 and 2Ec=25 kV/cm at an applied electric field 58 kV/cm was obtained because of lower breakdown voltage which maybe induced by lower relative density of the sample. A weak ferromagnetic (Mr=0.122 memu/g, Hc=69 Oe) rather than an antiferromagnetic property was observed at RT by magnetic measurement. Significantly, the ME coupling between the electric dipoles and magnetic dipoles at RT was demonstrated by measuring the effect of magnetic and DC electric poling on ferroelectric and magnetic hysteresis loops, respectively. Both Pr and Mr decreased after magnetic and DC electric poling. And the rate of Pr change decreased with increasing measuring electric field.

Influence of Annealing on the Surface Topography and Magnetic Properties of Thin Films of the FINEMET-Type Alloy

2015 ◽  
Vol 233-234 ◽  
pp. 699-704 ◽  
Author(s):  
Evgeniya Mikhalitsyna ◽  
Vasiliy Kataev ◽  
Pavel Geydt ◽  
Vladimir Lepalovsky ◽  
Erkki Lähderanta
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Scanning Probe Microscopy ◽  
Annealing Temperature ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Scanning Probe ◽  
Type Alloy ◽  
Treatment Conditions ◽  
Magnetic Hysteresis Loops

Surface structure and magnetic properties of thin films of the FINEMET-type alloy modificated by Mo (FeCuNbSiBMo) were studied in the aim of establishing of their dependence on heat treatment conditions. The thicknesses of the films were varied from 10 to 800 nm. Dependence of the microstructure of the films surface on the annealing temperature was analyzed using scanning probe microscopy. Parameters of the topography features were estimated as a function of the films thickness and annealing temperature. Magnetic hysteresis loops were measured using vibrating sample magnetometer and discussed in the focus of surface and thickness influences.

Preparation and Properties of Zn1-XCoxO Magnetic Microspheres

2010 ◽  
Vol 663-665 ◽  
pp. 1081-1084
Author(s):  
Zhi Fu Liu ◽  
Qing Hong Zhang ◽  
Li Yun Chen ◽  
Yao Gang Li ◽  
Hong Zhi Wang
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Magnetic Microspheres ◽  
Diffraction Field ◽  
Vibrating Sample Magnetometry ◽  
X Ray ◽  
Transmission Electron ◽  
Magnetic Hysteresis Loops

Zn1-xCoxO magnetic microspheres have been synthesized by a simple solvothermal process. Different Co2+ dopant concentrations have been used as modifier and proved to be efficient at controlling the morphology and magnetic property of Zn1-xCoxO microspheres. The as-synthesized samples are characterized by X-ray powder diffraction, field-emission scanning electron microscopy, transmission electron microscopy, photoluminescence spectrophotometer and vibrating sample magnetometry. Magnetic hysteresis loops reveal the samples exhibit ferromagnetic loops at room temperature. The meta-saturation magnetization value and coercivity of Zn0.8Co0.2O reach 0.09 emu·g-1 and 15.0 Oe.

Structure and Magnetic Properties of Ti-Co Co-Cubstituted Barium Hexaferrite

2014 ◽  
Vol 602-603 ◽  
pp. 951-955
Author(s):  
Zheng Qiang Zhang ◽  
Qing Lin Xia ◽  
Guang Hua Guo ◽  
Hai Fa Zhang ◽  
Cun Jun Dong
Keyword(s):  
Magnetic Properties ◽  
Substitution Rate ◽  
Magnetic Measurement ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Barium Hexaferrite ◽  
Particle Structure ◽  
Magnetic Hysteresis Loops ◽  
Xrd Patterns ◽  
Citrate Precursor

Polycrystalline Ti-Co co-substituted M-type ferrites Ba (TiCo)xFe12-2xO19 (x=0.25,0.5, 0.75, 1.0 ) samples were prepared by the citrate precursor method. The particle structure and morphology of the products were characterized by X-ray powder diffraction (XRD) and Field Emission Scanning Electron Microscope (FE-SEM). The effects of the substitution rate on the magnetic properties of samples were analysed by magnetic measurement with the Vibrating Sample Magnetometer (VSM) of Physical Properties Measurement System (PPMS). The XRD patterns show that only one type of crystalline phase can be detected and the substitution did not change the crystal structure. The SEM micrographs of Ba (TiCo)xFe12-2xO19 calcined at 450 °C for 5h, and then 950°C for 5h show that the M-type ferrite particles were homogeneously shaped and the grain sizes had no obvious differences when the substitution rate changed. The magnetic hysteresis loops illustrate that the coercivity (Hc) decreased rapidly with the increasing of Ti-Co substitution, while the saturation magnetization (Ms) changed slowly.

Correlation of Cooling Conditions with the Shape of Hysteresis Loops in Air Cooled and Quenched Axis Shaft

2015 ◽  
Vol 644 ◽  
pp. 223-226
Author(s):  
Angelos Tsoutsias
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Magnetic Properties ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Cooling Conditions ◽  
Magnetic Hysteresis Loops ◽  
Nondestructive Characterization ◽  
Scanning Electron

The present paper investigates the utilization of the magnetic hysteresis loops for the nondestructive characterization of annealed axis shaft samples. The resulting magnetic properties were further evaluated by examining the microstructure of the annealed samples by using scanning electron microscopy.

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