Effect of cerium substitution on structural and impedance properties of 0.8Ba0.2(Bi0.5K0.5)TiO3lead free ceramic system

2016 ◽  
Vol 30 (06) ◽  
pp. 1650056
Author(s):  
M. N. V. Ramesh ◽  
K. V. Ramesh
Keyword(s):  
Impedance Analysis ◽  
Solid State Reaction Method ◽  
High Energy ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Lead Free Ceramics ◽  
A Site

Cerium-doped 0.8BaTiO3-0.2Bi[Formula: see text]K[Formula: see text]TiO3with composition 0.8Ba0.2(Bi[Formula: see text]K[Formula: see text])Ti[Formula: see text]Ce[Formula: see text]O3where x = 0.01, 0.02, 0.03, 0.04, 0.05, 0.06 lead free ceramics were prepared by conventional solid state reaction method followed by high energy ball milling. X-ray diffraction studies confirm the tetragonal structure at room temperature for all the Ce-doped samples. Lattice parameters and density were increasing with increase of Ce doping. Frequency and temperature dependent dielectric studies were carried out and indicate that the dielectric constant and Curie temperature are decreasing with increasing of Ce doping. All the Ce-doped samples exhibiting diffused and dispersive phase transitions with degree of diffuseness ranging from 1.4 to 2 calculated from the modified Curie–Weiss law. Impedance studies confirms the temperature dependent non-Debye kind of relaxation process in the material. From the Cole–Cole plots measured at high temperatures, reveals that the grain effect in the all Ce-doped samples. Impedance analysis studies also support the X-ray diffraction and dielectric studies that occupation of Ce both at A-site and B-site for small values of Ce doping.

MULTIFERROIC MATERIALS Bi1-xSmxFeO3: A STUDY OF RAMAN AND ABSORPTION SPECTROSCOPIES

2010 ◽  
Vol 19 (02) ◽  
pp. 247-254 ◽  
Author(s):  
NGUYEN VAN MINH ◽  
DAO VIET THANG
Keyword(s):  
Lattice Dynamics ◽  
Optical Band Gap ◽  
Solid State Reaction Method ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Lattice Constants ◽  
Raman Measurement

Multiferroic Bi 1-x Sm x FeO 3(x = 0.00, 0.05, 0.1, 0.15, 0.2) ceramics were prepared by conventional solid state reaction method. X-ray diffraction measurement was carried out to characterize the crystal structure and to detect the impurities existing in these ceramics. The substitution of rare earth Sm for Bi was found to decrease the impurity phase in BiFeO 3 ceramics. There is strong evidence that both lattice constants a and c of the unit cell become smaller as the Sm 3+ content is increased. The effect of introducing Sm 3+ is shown to decrease the optical band gap for doped sample Bi 1-x Sm x FeO 3. Additionally, the temperature-dependent Raman measurement performed for the lattice dynamics study of Bi 1-x Sm x FeO 3 samples reveals a strong band centered at around 1000–1300 cm-1 which is associated with the resonant enhancement of two-phonon Raman scattering in the multiferroic Bi 1-x Sm x FeO 3 samples. This two-phonon signal is shown to broaden with increasing x. The Raman spectra at low wavenumbers are suggested to be related with magnon in this system.

scholarly journals Studies of phase transition and impedance behavior of Ba(Zr, Ti)O3 ceramics

2015 ◽  
Vol 05 (01) ◽  
pp. 1550002 ◽  
Author(s):  
P. Sateesh ◽  
J. Omprakash ◽  
G. S. Kumar ◽  
G. Prasad
Keyword(s):  
Phase Transition ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Phase Transition Behavior ◽  
Temperature Dependent ◽  
Conventional Solid State Reaction ◽  
Xrd Pattern ◽  
X Ray ◽  
Ceramic Samples ◽  
Barium Zirconium Titanate

Ceramic samples of Barium Zirconium Titanate ( BaZr x Ti 1-x O 3 ( BZT )) were synthesized by conventional solid-state reaction method with different concentrations of x(= 0.05 ( BZT1 ), 0.10 (BZT2), 0.15 (BZT3), 0.20 (BZT4), 0.25 (BZT5), 0.30 (BZT6)). Phase confirmation of the samples was done by X-ray diffraction (XRD) technique. All the compositions are in cubic structure. XRD pattern was recorded for samples sintered at different sintering temperatures. Lattice parameters increased with addition of Zr +4. Doping with Zr +4 into Barium titanate resulted in interesting changes of electrical properties (dielectric, impedance and ferroelectiricity). The strong influence of Zr doping on the phase transition characteristics of the BZT ceramics was studied from the dielectric response of the samples. Diffusivity of phase transition of the BZT ceramic samples increase with Zr +4 concentration, indicating changes from normal to diffuse transition to relaxor phase transition behavior. Impedance spectroscopy reveals the presence of temperature-dependent grain, grain boundary effects. Polarization–Electricfield (PE) loop measurements are also done on the samples.

Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Structural Information ◽  
Impedance Analysis ◽  
High Energy ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Powder Morphology ◽  
X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

scholarly journals Borate melt structure: Temperature‐dependent B–O bond lengths and coordination numbers from high‐energy X‐ray diffraction

2018 ◽  
Vol 101 (8) ◽  
pp. 3357-3371 ◽  
Author(s):  
Oliver L. G. Alderman ◽  
Chris J. Benmore ◽  
Alex Lin ◽  
Anthony Tamalonis ◽  
J. K. Richard Weber
Keyword(s):  
High Energy ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Melt Structure ◽  
X Ray ◽  
Coordination Numbers ◽  
Bond Lengths

Quaternary intermetallics RE2Pt3Ga4In (RE=Y, Gd-Tm) – intergrowth structures of NdRh2Sn4 and TiNiSi related slabs

2020 ◽  
Vol 235 (4-5) ◽  
pp. 117-125
Author(s):  
Myroslava Horiacha ◽  
Maximilian K. Reimann ◽  
Jutta Kösters ◽  
Vasyl‘ I. Zaremba ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystals ◽  
High Frequency ◽  
Magnetic Moments ◽  
Intermetallic Phases ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Arc Melting ◽  
Intergrowth Structures ◽  
A Site

AbstractThe quaternary gallium-rich intermetallic phases RE2Pt3Ga4In with RE = Y and Gd-Tm were synthesized by arc-melting of the elements and subsequent annealing. Small single crystals were obtained by high-frequency annealing of the samples in sealed tantalum ampoules. The polycrystalline samples were characterized through their X-ray powder patterns. The RE2Pt3Ga4In phases crystallize with a site ordering variant of the orthorhombic Y2Rh3Sn5 type, space group Cmc 21. The structures of Gd2Pt3Ga4In, Dy2Pt3Ga4.14In0.86, Er2Pt3Ga4.17In0.83 and Tm2Pt3Ga4.21In0.79 were refined from single-crystal X-ray diffraction data. The single crystals reveal small homogeneity ranges RE2Pt3Ga4±xIn1±x. The striking geometrical structural building units are slightly distorted trigonal prisms around the three crystallographically independent platinum atoms: Pt1@RE4Ga2, Pt2@RE2Ga4 and Pt3@RE2Ga2In2. Based on these prismatic building units, the RE2Pt3Ga4In structures can be described as intergrowth variants of TiNiSi and NdRh2Sn4 related structural slabs. Temperature dependent magnetic susceptibility studies of Gd2Pt3Ga4In and Tb2Pt3Ga4In show Curie-Weiss behavior and the experimental magnetic moments confirm stable trivalent gadolinium respectively terbium. Gd2Pt3Ga4In and Tb2Pt3Ga4In order antiferromagnetically at TN = 15.8(1) and 26.0(1) K. Magnetization curves at 3 K show field-induced spin reorientations.

scholarly journals Dielectric and Raman studies of Ba0.06(Na1/2Bi1/2)0.94TiO3–NaNbO3 ceramics

2016 ◽  
Vol 34 (2) ◽  
pp. 437-445 ◽  
Author(s):  
Sumit K. Roy ◽  
S. Chaudhuri ◽  
R.K. Kotnala ◽  
D.K. Singh ◽  
B.P. Singh ◽  
...  
Keyword(s):  
Single Phase ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Orthorhombic Symmetry ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
New Phase ◽  
Diffusivity Parameter

AbstractIn this work the X-ray diffraction, scanning electron microscopy, Raman and dielectric studies of lead free perovskite (1 – x)Ba0.06(Na1/2Bi1/2)0.94TiO3–xNaNbO3 (0 ⩽ x ⩽ 1.0) ceramics, prepared using a standard solid state reaction method, were investigated. X-ray diffraction studies of all the ceramics suggested the formation of single phase with crystal structure transforming from rhombohedral-tetragonal to orthorhombic symmetry with the increase in NaNbO3 content. Raman spectra also confirmed the formation of solid solution without any new phase. Dielectric studies showed that the phase transition is of diffusive character and diffusivity parameter decreases with increasing NaNbO3 content. The compositional fluctuation was considered to be the main cause of diffusivity.

Temperature Dependence on Dielectric Response of La0.7Ba0.3Mn0.4Ti0.6O3 Ceramic

2015 ◽  
Vol 1107 ◽  
pp. 45-52
Author(s):  
Aaliyawani Ezzerin Sinin ◽  
Walter Charles Primus ◽  
Abdul Halim Shaari ◽  
Zainal Abidin Talib ◽  
Sinin Hamdan
Keyword(s):  
Dielectric Properties ◽  
Temperature Dependence ◽  
Low Frequency ◽  
Sintered Sample ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Low Frequencies ◽  
X Ray ◽  
Lcr Meter

Ceramic sample of La0.70Ba0.30Mn0.40Ti0.60O3 oxide has been prepared by the conventional solid-state reaction method. The sintered sample was characterized by using x-ray diffraction (XRD) and low frequency LCR meter. XRD result shows that the sample has a cubic structure with the existence of impurity phase. The dielectric properties of La0.70Ba0.30Mn0.40Ti0.60O3 measured from room temperature to 200°C shows that the dielectric permittivity is temperature dependence with strong dispersion at low frequencies. A circuit model based on the universal capacitor response function is also being used to represent the dielectric properties of the sample.

Photoluminescence properties of Na1.45La8.55(SiO4)6(F0.9O1.1):Eu for applications as a reddish orange phosphor

2014 ◽  
Vol 07 (05) ◽  
pp. 1450060 ◽  
Author(s):  
Qun Shi ◽  
Dhia A. Hassan ◽  
Renjie Zeng
Keyword(s):  
Spectral Analysis ◽  
Solid State Reaction Method ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
X Ray ◽  
Analysis System ◽  
Reddish Orange ◽  
The Eu

Europium-doped Na 1.45 La 8.55-8.55x( SiO 4)6( F 0.9 O 1.1)(0.000 ≤ x ≤ 0.045) phosphors were prepared by a conventional solid-state reaction method at 1200°C and their properties were studied by X-ray diffraction (XRD), and a spectral analysis system. No impurities were observed. The phosphor could be excited at 254 nm, 395 nm and 465 nm to yield a reddish orange emission which was attributed to the 5 D 0 → 7 F j (j = 0–2) transitions of the Eu ion.

scholarly journals Structural, microstructural and dielectric characterizations of (Bi0.5Na0.5)TiO3based lead-free ferroelectric ceramics

2021 ◽  
pp. 2140006
Author(s):  
B. R. Moya ◽  
A. C. Silva ◽  
A. Peláiz-Barranco ◽  
J. D. S. Guerra
Keyword(s):  
Lead Free ◽  
Ferroelectric Ceramics ◽  
Reaction Sintering ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Porosity Level ◽  
X Ray ◽  
Ceramic Samples ◽  
Lead Free Ceramics ◽  
Sintering Method

(1–[Formula: see text]Bi[Formula: see text]Na[Formula: see text]TiO3–[Formula: see text]BaTiO3 lead-free ceramics have been obtained from the conventional solid-state reaction sintering method. The structural properties were investigated from X-ray diffraction and Raman spectroscopy techniques. Results revealed well-crystallized ceramic samples with perovskite structure. Microstructural properties, obtained from scanning electron microscopy measurements, have shown high density with very low porosity level. The dielectric response, analyzed as a function of the temperature and several frequencies, showed very broad peaks with a strong frequency dependence of the temperature for the maximum dielectric permittivity for the modified system. Results were analyzed considering the influence of the BaTiO3 content on the studied physical properties.

Structural, dielectric, ferroelectric and impedance spectroscopic studies on Ba1−xSrxTiO3(0.15 ≤ x ≤ 0.35)

2019 ◽  
Vol 33 (17) ◽  
pp. 1950193 ◽  
Author(s):  
Shukdev Pandey ◽  
Om Parkash ◽  
Devendra Kumar
Keyword(s):  
Equivalent Circuit Model ◽  
Solid State Reaction Method ◽  
Spectroscopic Studies ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
X Band ◽  
Xrd Patterns ◽  
Diffuse Phase

Compositions with x = 0.15, 0.20, 0.25, 0.30 and 0.35 were synthesized in the system [Formula: see text] using conventional solid state reaction method and characterized by X-Ray Diffraction (XRD), Raman spectroscopy and Scanning Electron Microscopy (SEM). Tetragonal phase was confirmed in all the samples using Rietveld refinement of the XRD patterns and observation of their Raman spectra. Dielectric and impedance measurements were carried out in the temperature range 300–723 K in the frequency range 1 Hz to 1 MHz. The samples exhibit diffuse phase transition (DPT). Equivalent circuit model involving combination of Constant Phase angle Elements (CPE) and resistances (R) was developed which represents the data well. Expressions for the values of resistances (R) were established in terms of composition and temperature empirically. P-E loops indicated normal ferroelectric behavior for all the samples. Dielectric constant was also measured in the frequency range 8–12 GHz in the X band of microwaves.

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