scholarly journals Influence of the PbO-excess on the structural, microstructural and ferroelectric properties of PLZT ceramics

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
A.C. Silva ◽  
Y. Mendez-Gonzalez ◽  
E.C. Lima ◽  
J.D.S. Guerra
Keyword(s):  
Strong Influence ◽  
Ferroelectric Properties ◽  
Secondary Phase ◽  
Long Range Order ◽  
X Ray Diffraction ◽  
Lead Lanthanum Zirconate Titanate ◽  
Lanthanum Zirconate ◽  
X Ray ◽  
Spectroscopy Studies ◽  
Rhombohedral Symmetry

The physical properties of lead lanthanum zirconate titanate (PLZT) ceramics have been investigated as a function of a PbO excess from 0 to 20 mol% in samples of Pb0.94La0.06(Zr0.6895Ti0.2955)O3 (composition that reveals the best performance for piezoelectric applications for materials with rhombohedral symmetry). Results are presented in a compressive way in the frame of an overview on PLZT. Structural, microstructural and ferroelectric properties were investigated as a function of the PbO content. The X-ray diffraction results confirmed the formation of the perovskite structure for all the cases. However, the presence of the Pb2O3 secondary phase has been observed for the sample containing 15 mol% PbO excess. Raman spectroscopy studies revealed a strong influence of the PbO content on the active modes shifts. The ferroelectric properties have shown a decrease of both remnant (PR) and saturation (PS) polarizations for compositions up to 10 mol% PbO, whereas an increase of PR and PS was observed for the higher PbO content samples. Results reveal the effect of the PbO excess on the long-range order interactions for the studied system.

Perovskite Relaxor Ferroelectric Thick Films Directly Grown from Oxide Precursors by a Low Temperature Hydrothermal Process

2007 ◽  
Vol 334-335 ◽  
pp. 1049-1052
Author(s):  
Hui Qing Fan ◽  
Xiu Li Chen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Thick Films ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Lead Lanthanum Zirconate Titanate ◽  
Lanthanum Zirconate ◽  
X Ray ◽  
Morphological Studies ◽  
Phase Characterization

Relaxor-based lead-lanthanum-zirconate-titanate (PLZT) thick films were prepared on Ti substrates by a simplified hydrothermal method, in which the precursors were heated to 150 oC with durations from 8 to 32h. The mixture of oxides was used as the staring materials. The smooth PLZT films with a single perovskite structure were obtained through the synthesis route. Structural and morphological studies were carried out on hydrothermally synthesized films. The influences of the mineralizer concentration on the structural, morphological, and physical characteristics of the particles are studied. Phase characterization and crystal orientation of the PLZT thick films were investigated by x-ray diffraction analysis (XRD). The dielectric constant and dielectric loss of the PLZT thick films were measured. In the frequency range from 1000 to 100 MHz, the dielectric constant and the dielectric loss were very steady.

Ferroelectric Properties of Bi0.5(Na0.8K0.2)0.5TiO3 Ceramics

2014 ◽  
Vol 975 ◽  
pp. 3-8 ◽  
Author(s):  
Javier Camargo ◽  
Leandro Ramajo ◽  
Fernando Rubio-Marcos ◽  
Miriam Castro
Keyword(s):  
Sintering Temperature ◽  
Ferroelectric Properties ◽  
Secondary Phase ◽  
Processing Conditions ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Density Measurements ◽  
X Ray ◽  
Xrd Patterns

Different processing conditions and the effect of secondary phases on ferroelectric properties of Bi0.5(Na0.8K0.2)0.5TiO3(BNKT) are studied. Ceramic powders are prepared by solid state reaction and different sintering temperatures (temperatures between 1075 and 1150°C) are analyzed. Finally, samples are characterized by X-ray diffraction, Raman microspectroscopy, Scanning Electron Microscopy, impedance spectroscopy, and density measurements. Through XRD patterns, the perovskite structure is stabilized; together with small peaks corresponding to a secondary phase associated with K2-xNaxTi6O13phase. Moreover, the content of the secondary phase, d33piezoelectric constant and dielectric properties increase with sintering temperature.

scholarly journals Synthesis, microstructure and dielectric properties of Sb-doped multiferroic Bi0.8Ba0.2Fe1−xSbxO3 ceramics

2019 ◽  
Vol 09 (04) ◽  
pp. 1950030
Author(s):  
Doreir Benzebeiri ◽  
Chahrazed Benhamideche ◽  
Youghourta Belhocine ◽  
Abdelghani May ◽  
Salah-Eddine Bouaoud ◽  
...  
Keyword(s):  
Solid Phase ◽  
Ferroelectric Properties ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Sb Doping ◽  
Rhombohedral Symmetry

The multiferroic ceramics Bi[Formula: see text]Ba[Formula: see text]Fe[Formula: see text]SbxO3 with [Formula: see text], 0.01, and 0.02 were synthesized using the solid-phase reaction technique. The samples were sintered at two different temperatures, 850∘C and 900∘C. Scanning electron microscopy revealed the effect of antimony concentration on grain size and formation. The effect of Sb-doping on the crystal structure and ferroelectric properties of these ceramics was investigated using X-ray diffraction, Raman spectroscopy, and dielectric measurements. The dielectric constant was enhanced upon Fe[Formula: see text] substitution by Sb[Formula: see text] without affecting the dielectric loss of the ceramics. The tetragonal distortion of the rhombohedral symmetry of BiFeO3 caused by Ba-doping at Bi[Formula: see text] site was lifted by Sb-doping at Fe[Formula: see text] site.

Magnetic Properties of Bulk Zn0.95-XMnXFe0.05O2 Prepared by Sol-Gel Method and Subsequent Hot Pressing

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Sol Gel ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.

Influence of LaNiO3 as an Electrode on the Properties of Ferroelectric Oxides

2000 ◽  
Vol 623 ◽  
Author(s):  
R. Kalare ◽  
M. Vedawyas ◽  
A. Kumar
Keyword(s):  
Ferroelectric Properties ◽  
Ferroelectric Thin Film ◽  
Memory Device ◽  
Epitaxial Films ◽  
Laser Deposition ◽  
Oxide Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Potential Electrode ◽  
Ferroelectric Oxides

AbstractAn electrode plays an important role in realising a ferroelectric thin film as a potential memory device. We have investigated LaNiO3 (LNO) as a potential electrode material and evaluated the ferroelectric properties of oxide materials like strontium bismuth tantalate (SBT) and barium titanate(BT). We have successfully deposited epitaxial films of LNO on Pt coated Si(100) and LaAlO3 (LAO) substrates using the pulsed excimer laser deposition technique. We are able to grow high quality SBT and BT films on top of this LNO layer. The X-ray diffraction revealed the epitaxy of the LNO, SBT and BT films. The ferroelectric properties of SBTand BT were investigated using the RT66A ferroelectric tester.

scholarly journals Термодинамические свойства оксипентафторида ванадия (IV), (NH-=SUB=-4-=/SUB=-)-=SUB=-3-=/SUB=-VOF-=SUB=-5-=/SUB=-

2020 ◽  
Vol 62 (7) ◽  
pp. 1123
Author(s):  
Е.В. Богданов ◽  
Е.И. Погорельцев ◽  
А.В. Карташев ◽  
М.В. Горев ◽  
М.С. Молокеев ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Photoelectron Spectroscopy ◽  
Single Phase ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Limits Of Stability ◽  
Three Phase ◽  
Temperature Dependences ◽  
Spectroscopy Studies

Abstract The (NH_4)_3VOF_5 crystals have been synthesized and their homogeneity and single-phase structure has been established by the X-ray diffraction, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy studies. The investigations of the temperature dependences of specific heat, entropy, strain, and pressure susceptibility show the occurrence of three phase transitions caused by the structural transformations in the (NH_4)_3VOF_5 crystals. The T – p phase diagram shows the temperature limits of stability of the crystalline phases implemented in (NH_4)_3VOF_5. The optical and dielectric studies disclose the ferroelastic nature of the phase transitions. An analysis of the experimental data together with the data on the isostructural (NH_4)_3VO_2F_4 crystal makes it possible to distinguish the physical properties of oxyfluorides containing vanadium of different valences (IV and V).

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