Structural, Magnetic, and Ferroelectric Properties in Ion-Doped BiFeO3 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 391-395
Author(s):  
Shu Xia Zhang ◽  
Yan Wei Ma
Keyword(s):  
Ferroelectric Properties ◽  
Sol Gel ◽  
Structural Phase ◽  
Magnetic Hysteresis ◽  
Synthesis Method ◽  
Secondary Phase ◽  
Rare Earth Ion ◽  
La Doping ◽  
Auto Combustion ◽  
La Doped

Rare-earth ion La is doped at the bismuth site in BiFeO3 to produce Bi0.8La0.2FeO3 polycrystalline ceramics via a sol-gel auto-combustion synthesis method. For comparison, the similar experiments are also carried out for the non-doped BiFeO3 at the same time. It is found that both non-doped and La doped BiFeO3 are composed of nanoscale crystallites (~50 nm). Furthermore, La doping suppresses the formation of the secondary phase and leads to a structural phase transition from a rhombohedral to an orthorhombic or a pseudotetragonal structure. More importantly, the magnetic and ferroelectric properties in La doped ceramics were both enhanced, as evidenced by the typical electric and magnetic hysteresis loops. These property evolutions can be attributed to the elimination of the secondary phase and the structural distortion caused by La doping.

scholarly journals Green synthesis and characterization of hexaferrite strontium-perovskite strontium photocatalyst nanocomposites

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi
Keyword(s):  
Magnetic Properties ◽  
Green Synthesis ◽  
Sol Gel ◽  
Synthesis Method ◽  
Combustion Method ◽  
Lemon Juice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

Effect of sol–gel synthesis method on the structural, electrical, and ferroelectric properties of lead-free K0.5Na0.5NbO3 ceramic

2019 ◽  
Vol 92 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Shammi Kumar ◽  
Mamta Shandilya ◽  
Shweta Thakur ◽  
Nagesh Thakur ◽  
Gun Anit Kaur
Keyword(s):  
Ferroelectric Properties ◽  
Sol Gel ◽  
Synthesis Method ◽  
Lead Free ◽  
Sol Gel Synthesis

Synthesis and microwave absorbing properties of La-doped Sr-hexaferrite nanopowders via sol–gel auto-combustion method

Rare Metals ◽  
2015 ◽  
Vol 36 (9) ◽  
pp. 704-710 ◽  
Author(s):  
Jun-Liang Liu ◽  
Peng Zhang ◽  
Xing-Kai Zhang ◽  
Qing-Qing Xie ◽  
Dong-Jun Pan ◽  
...  
Keyword(s):  
Sol Gel ◽  
Combustion Method ◽  
Microwave Absorbing Properties ◽  
Auto Combustion ◽  
Microwave Absorbing ◽  
La Doped

scholarly journals Dielectric and ferroelectric properties of CoCr2O4 nanoceramics

2019 ◽  
Vol 09 (03) ◽  
pp. 1950015 ◽  
Author(s):  
Pankaj Choudhary ◽  
P. Saxena ◽  
A. Yadav ◽  
V. N. Rai ◽  
A. Mishra
Keyword(s):  
Leakage Current ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Complex Impedance ◽  
Interfacial Polarization ◽  
Nyquist Plot ◽  
Dielectric Parameters ◽  
Electron Conduction ◽  
Auto Combustion ◽  
Current Behavior

CoCr2O4 nanoceramics are prepared by sol–gel auto combustion method. Synchrotron X-ray diffraction analysis affirms the single-phase pristine cubic structure with space group [Formula: see text]. Debye–Scherrer method estimates the crystallite size of main intense peak to be [Formula: see text][Formula: see text]nm. Prominent bands obtained in infrared spectra at 448 and 599[Formula: see text]cm[Formula: see text] are due to metal–oxygen stretching bond present at tetrahedral and octahedral sites. Dielectric parameters decrease as frequency increases from [Formula: see text] to [Formula: see text][Formula: see text]Hz that can be interpreted by Maxwell–Wagner-type interfacial polarization. Complex impedance spectra (Nyquist plot) reveal arc like behavior, which is mainly due to intergrain (grain boundary) resistance that also exhibits conducting nature of the nanoceramics. Weak ferroelectricity is mainly associated with the partial reversal of the polarization. Leakage current behavior follows the Ohmic and Child square law. Electron conduction process was interpreted by space-charge limited current (SCLC) mechanism. Leakage current behavior observed in cobalt chromite nanoceramics is mainly attributed to the oxygen vacancies.

Characterization of Plzt on Platinum Electrodes for High Density Fram Application

1996 ◽  
Vol 446 ◽  
Author(s):  
YongSoo Choi ◽  
SooDoo Choe ◽  
SeungHyun Kim ◽  
ChangEun Kim ◽  
DooYoung Yang
Keyword(s):  
Thin Film ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Stable State ◽  
Chelating Agent ◽  
Platinum Electrodes ◽  
Grain Sizes ◽  
Plzt Thin Film ◽  
La Doped

AbstractA new sol‐gel route to obtain PLZT thin film was developed by combining the advantage of 2‐methoxyethanol as a solvent and acetylacetone as a chelating agent. The sol maintained the same stable state as that of fresh synthesized sol even after 60 days of aging. The PLZT films spin coated onto a Pt/Ti/SiO2 substrate with 15% Pb excess and 7.5% La added sol showed well developed rosette microstructure of uniform grain sizes(0.3 ‐ 0.5 μm) and gave well behaved ferroelectric properties with the values of Ps, Pr, and Ec of 40 μC/cm2, 15 μ C/cm2, and 20 kV/cm respectively at 5V after 650 °C and above annealing. The degradation in polarization of 2.5% La doped PLZT thin film was found to be less than 20% up to 1012 cycles

The Role of Processing Parameters in Variation of Microstruture of Sol-Gel Derived Lead Zirconate Titanate Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
Chang Jung Kim ◽  
Tae-Young Kim ◽  
Ilsub Chung ◽  
In Kyung Yoo
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Secondary Phase ◽  
Processing Parameters ◽  
Lead Zirconate ◽  
Test System ◽  
Pzt Thin Films ◽  
Force Microscopy

AbstractThe PZT thin films were fabricated to investigate the effect of sol-gel processing parameters on the physical and the electrical properties. The films were made with different amount of excess Pb precursors and drying temperatures, and then annealed in various ambients. The physical properties of the films such as crystallinity and microstructure were evaluated using x-ray diffraction, scanning electron microscopy and atomic force microscopy. The ferroelectric properties and current density characteristics of the films were investigated using a standarized feiroelectric test system and pA meter, respectively. It is found that the drying temperature was playing a key role in the formation of the secondary phase on the PZT thin films. In addition, it turned out that the use of nitrogen as an annealing ambient promoted overall ferroelectric properties, when compared to oxygen ambients.

scholarly journals Preparation of Magneto Electric (Bafe12o19 / Bifeo3) Composites using Sol-Gel Auto Combustion Method

2019 ◽  
Vol 8 (11) ◽  
pp. 1484-1487
Keyword(s):  
Single Phase ◽  
Bismuth Ferrite ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Combustion Method ◽  
Systematic Change ◽  
Auto Combustion ◽  
Sem Micrograph ◽  
New Type ◽  
Composite Samples

The coexistence of ferromagnetic and ferroelectric properties in single phase material leads to the existence of new type of material known as magnetoelectric. In present work, magneto electric composites BaFe12O19 / BiFeO3 with different mass percentage of BiFeO3 (0, 25%, 50%, 75% and 100 %) were prepared. BaFe12O19 (BHF) and BiFeO3 (BiF) ferrites were prepared separately using Sol-gel auto combustion method and then physically mixed. Prepared composite samples were characterized using FTIR, XRD, SEM and VSM. XRD spectra reveal the mixed hexaferrite and bismuth ferrite phases. SEM micrograph of showed the formation of porous clusters of non uniform grains in the composites. Saturation magnetization of BaFe12O19 / BiFeO3 composites decreased gradually with increasing in BiFeO3 content and there is no systematic change in coercivity values

scholarly journals Magnetic Properties and Morphology Copper-Substituted Barium Hexaferrites from Sol-Gel Auto-Combustion Synthesis

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5873
Author(s):  
Abdulmumeen Lohmaah ◽  
Komkrich Chokprasombat ◽  
Supree Pinitsoontorn ◽  
Chitnarong Sirisathitkul
Keyword(s):  
Magnetic Properties ◽  
Combustion Synthesis ◽  
Permanent Magnets ◽  
Sol Gel ◽  
Barium Hexaferrite ◽  
Secondary Phase ◽  
Cost Effective ◽  
Partial Substitution ◽  
Cu Substitution ◽  
Auto Combustion

The copper (Cu) substitution in barium hexaferrite (BaFe12O19) crystals from the sol-gel auto-combustion synthesis is demonstrated as a cost-effective pathway to achieve alterable magnetic properties. Subsequent heat treatments at 450 °C and 1050 °C result in irregularly shaped nanoparticles characterized as the M-type BaFe12O19 with the secondary phase of hematite (α-Fe2O3). Despite the mixed phase, the substantial coercivity of 2626 Oe and magnetization as high as 74.8 emu/g are obtained in this undoped ferrite. The copper (Cu) doing strongly affects morphology and magnetic properties of BaFe12−xCuxO19 (x = 0.1, 0.3, and 0.5). The majority of particles become microrods for x = 0.1 and microplates in the case of x = 0.3 and 0.5. The coercivity and magnetization tend to reduce as Cu2+ increasingly substitutes Fe3+. From these findings, magnetic properties for various applications in microwave absorbers, recording media, electrodes, and permanent magnets can be tailored by the partial substitution in hexaferrite crystals.

Sign in / Sign up

Export Citation Format

Share Document