scholarly journals Synthesis and electrical characterization of Ca2Nd4Ti6O20 ceramics

2016 ◽  
Vol 34 (1) ◽  
pp. 164-168
Author(s):  
Raz Muhammad ◽  
Muhammad Uzair ◽  
M. Javid Iqbal ◽  
M. Jawad Khan ◽  
Yaseen Iqbal ◽  
...  
Keyword(s):  
Activation Energy ◽  
Dielectric Constant ◽  
Room Temperature ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Sintered Sample ◽  
First Time ◽  
Alkoxide Precursors ◽  
Room Temperature Dielectric Constant

AbstractCa2Nd4Ti6O20, a layered perov skite structured material was synthesized via a chemical (citrate sol-gel) route for the first time using nitrates and alkoxide precursors. Phase analysis of a sample sintered at 1625 °C revealed the formation of an orthorhombic (Pbn21) symmetry. The microstructure of the sample after sintering comprised rod-shaped grains of a size of 1.5 to 6.5µm. The room temperature dielectric constant of the sintered sample was 38 at 100 kHz. The remnant polarization (Pr) and the coercive field (Ec) were about 400 μC/cm2 and 8.4 kV/cm, respectively. Impedance spectroscopy revealed that the capacitance (13.7 pF) and activation energy (1.39 eV) of the grain boundary was greater than the capacitance (5.7 pF) and activation energy (1.13 eV) of the grain.

Electrical Characterization of Sol-Gel Derived PZT Films

1991 ◽  
Vol 243 ◽  
Author(s):  
G. Teowee ◽  
J.M. Boulton ◽  
S.C. Lee ◽  
D.R. Uhlmann
Keyword(s):  
Dielectric Constant ◽  
Low Temperatures ◽  
Lead Acetate ◽  
Single Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Electrical Characterization ◽  
Aging Rate ◽  
Pzt Films

AbstractSol-gel derived PZT films were successfully prepared from precursor solutions based on lead acetate and Zr/Ti alkoxides. A pyrochlore phase was observed in films fired at low temperatures, while single-phase perovskite films were obtained at temperatures above 725C. The dielectric constant increased to above 1000 when there was a higher proportion of perovskite than pyrochlore. The films were essentially fatigue-free up to 108 cycles and exhibited a low aging rate of 5.7% / decade-sec.

Characterization Of Sol-Gel Derived Tantalum Oxide Films

1986 ◽  
Vol 73 ◽  
Author(s):  
L. A. Silverman ◽  
G. Teowee ◽  
D. R. Uhlmann
Keyword(s):  
Dielectric Constant ◽  
Original Film ◽  
Room Temperature ◽  
Sol Gel ◽  
Tantalum Oxide ◽  
Leakage Currents ◽  
Applied Fields ◽  
Mis Capacitors ◽  
Hydrolysis Of

ABSTRACTWe have studied the densification and dielectric properties of sol-gel derived tantalum oxide thin films as the insulators in MIS capacitors. Hydrolysis of tantalum ethoxide is extremely rapid and goes to completion in ethanol. Condensation is also rapid, and goes to completion in toluene Multiple layers were applied by spin-coating up to thicknesses of 3000 Å before cracking of the coating during drying ensued. Densification occurs from room temperature to 450 C, with the original film thickness decreasing by about half in one hour at 450 C. No additional densification occurs upon heating to 750 C. The dielectric constant decreases from unfired samples to those fired at 450 C, and then increases on firing from 600 to 750 C. The value of the dielectric constant at 1 MHz for samples fired at 750 C for one hour is 20, similar to that of anodically grown Ta2O5. Leakage currents as low as 2 × 10−7 amp cm−2 have been measured for applied fields of 200,000 V cm−1.

Influence of sintering technique on the characteristics of Li–Co nanoferrites

2017 ◽  
Vol 31 (33) ◽  
pp. 1750314 ◽  
Author(s):  
Maisnam Victory ◽  
Mamata Maisnam ◽  
Sumitra Phanjoubam
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Room Temperature ◽  
Sol Gel ◽  
Conventional Technique ◽  
Vibrating Sample Magnetometer ◽  
Microstructural Properties ◽  
Room Temperature Dielectric Constant ◽  
Scanning Electron

Li–Co nanoferrites (Li[Formula: see text]Co[Formula: see text]Fe[Formula: see text]O4) with x = 0.00, 0.03, 0.06, 0.09, and 0.12, were synthesized by chemical sol–gel method. Two different sintering techniques viz. conventional technique (CT) and microwave technique (MT) were employed to heat treat the synthesized samples with an aim to study the effect of sintering technique on the properties of the nanoferrites. Structural and microstructural properties of the samples were investigated using XRD and scanning electron microscopy (SEM) technique, respectively. The variation of room temperature dielectric constant and dielectric loss were measured as a function of frequency in the range 100 Hz–1 MHz and the normal dispersive behavior was observed. Magnetic properties were investigated using Vibrating Sample Magnetometer (VSM), while Soohoo’s method was used to measure Curie temperature. The results obtained have been discussed in the paper.

Characterization of Sol-Gel Derived Tantalum Oxide Films

1986 ◽  
Vol 72 ◽  
Author(s):  
L. A. Silverman ◽  
G. Teowee ◽  
D. R. Uhlmann
Keyword(s):  
Dielectric Constant ◽  
Original Film ◽  
Room Temperature ◽  
Sol Gel ◽  
Tantalum Oxide ◽  
Leakage Currents ◽  
Applied Fields ◽  
Mis Capacitors ◽  
Hydrolysis Of

AbstractWe have studied the densification and dielectric properties of sol-gel derived tantalum oxide thin films as the insulators in MIS capacitors. Hydrolysis of tantalum ethoxide is extremely rapid and goes to completion in ethanol. Condensation is also rapid, and goes to completion in toluene Multiple layers were applied by spin-coating up to thicknesses of 3000 Å before cracking of the coating during drying ensued. Densification occurs from room temperature to 450 C, with the original film thickness decreasing by about half in one hour at 450 C. No additional densification occurs upon heating to 750 C. The dielectric constant decreases from unfired samples to those fired at 450 C, and then increases on firing from 600 to 750 C. The value of the dielectric constant at 1 MHz for samples fired at 750 C for one hour is 20, similar to that of anodically grown Ta2O5. Leakage currents as low as 2 × 10−7 amp cm−2 have been measured for applied fields of 200,000 V cm−1.

Characterization of SrBi2Nb2O9 Thin Films Prepared by Sol Gel Technique

1996 ◽  
Vol 459 ◽  
Author(s):  
E. Ching-Prado ◽  
W. Pérez ◽  
A. Reynés-Figueroa ◽  
R. S. Katiyar ◽  
D. Ravichandran ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Band ◽  
Sol Gel ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Gel Technique ◽  
High Degree ◽  
First Time

ABSTRACTThin films of SrBi2Nb2O9 (SBN) with thicknesses of 0.1, 0.2, and 0.4 μ were grown by Sol-gel technique on silicon, and annealed at 650°C. The SBN films were investigated by Raman scatering for the first time. Raman spectra in some of the samples present bands around 60, 167, 196, 222, 302, 451, 560, 771, 837, and 863 cm−1, which correspond to the SBN formation. The study indicates that the films are inhomogeneous, and only in samples with thicknesses 0.4 μ the SBN material was found in some places. The prominent Raman band around 870 cm−1, which is the A1g mode of the orthorhombic symmetry, is assigned to the symmetric stretching of the NbO6 octahedrals. The frequency of this band is found to shift in different places in the same sample, as well as from sample to sample. The frequency shifts and the width of the Raman bands are discussed in term of ions in non-equilibrium positions. FT-IR spectra reveal a sharp peak at 1260 cm−1, and two broad bands around 995 and 772 cm−1. The bandwidths of the latter two bands are believed to be associated with the presence of a high degree of defects in the films. The experimental results of the SBN films are compared with those obtained in SBT (T=Ta) films. X-ray diffraction and SEM techniques are also used for the structural characterization.

Fabrication and electrical characterization of transparent NiO/ZnO p–n junction by the sol–gel spin coating method

2012 ◽  
Vol 64 (1) ◽  
pp. 219-223 ◽  
Author(s):  
M. Cavas ◽  
R. K. Gupta ◽  
A. A. Al-Ghamdi ◽  
Omar A. Al-Hartomy ◽  
Farid El-Tantawy ◽  
...  
Keyword(s):  
Spin Coating ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Spin Coating Method ◽  
Coating Method

Electrical characterization of room temperature humidity sensors in La0.8Sr0.2Fe1−xCuxO3 (x=0, 0.05, 0.10)

2012 ◽  
Vol 38 (4) ◽  
pp. 2865-2872 ◽  
Author(s):  
A. Cavalieri ◽  
T. Caronna ◽  
I. Natali Sora ◽  
J.M. Tulliani
Keyword(s):  
Room Temperature ◽  
Electrical Characterization ◽  
Humidity Sensors

Pyroelectric Properties of the Plt(10) Thin Film on the P-Doped Poly Silicon

1996 ◽  
Vol 433 ◽  
Author(s):  
Seong Jun Kang ◽  
Yung Sup Yoon ◽  
Dong Il Kim
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Curie Temperature ◽  
Room Temperature ◽  
Sol Gel ◽  
Pyroelectric Coefficient ◽  
Pyroelectric Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Poly Silicon

AbstractWe have studied the pyroelectric properties of the PLT(10) thin film deposited on a p-doped poly-Si electrode by using the sol-gel method. Measurement of the dielectric constant as a function of temperature shows the typical characteristics of a ferroelectric. The dielectric constant reaches a maximum at 295°C, which can be thought of as the Curie temperature. The PLT(10) thin film on p-doped poly-Si fabricated in this research shows excellent pyroelectric properties. The pyroelectric coefficient and the fiqures of merit, Fv and FD at room temperature are measured as 5.76 × 10−8 C/cm2 °C, 1.17 × 10−10C-cm/J and 0.93 × 10−8C-cm/J, respectively.

Synthesis and characterization of MnO2nanowires

2017 ◽  
Vol 31 (02) ◽  
pp. 1750006 ◽  
Author(s):  
Mohammad Hossein Ghorbani ◽  
Abdol Mahmood Davarpanah
Keyword(s):  
Lithium Batteries ◽  
Manganese Oxides ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrd Method

Manganese oxides are of more interest to researchers because of their ability as catalysts and lithium batteries. In this research, MnO2nanowires with diameter about 45 nm were synthesized by sol–gel method at room temperature (RT). Effect of increasing the annealing temperature from 400[Formula: see text]C to 600[Formula: see text]C on crystalline structure of nanostructure were studied and average crystallite size was estimated about 22 nm. X-ray Diffraction (XRD) method, Energy-Dispersive X-ray Diffraction (EDXD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM) were used to characterize the nanowires of MnO2.

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