scholarly journals Preparation of ZnO film on p-Si Substrate by Silar and Heterojunction Characteristics of p-Si/n-Zno

2011 ◽  
Vol 8 (1) ◽  
pp. 197-200 ◽  
Author(s):  
P. Mitra
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Reverse Current ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Si Substrate ◽  
Current Ratio ◽  
Axis Orientation ◽  
X Ray ◽  
Maximum Value

Zinc oxide (ZnO) thin films was deposited on p-silicon (Si) substrate from ammonium zincate bath following a chemical dipping technique called SILAR. Structural characterization by X-ray diffraction (XRD) indicates the formation of polycrystalline single phase ZnO with strong c-axis orientation. I-V characteristic of the p-Si/n-ZnO heterojunction was studied and rectification was observed. The maximum value of forward to reverse current ratio at room temperature was ~15 at 3.0 V. It increases to ~30 at 100oC.

Preparation of Na0.5K0.5NbO3/La0.6Sr0.2Mn1.2O3/LaAlO3 Thin Film Structures by Pulsed Laser Deposition

1999 ◽  
Vol 574 ◽  
Author(s):  
Choong-Rae Cho ◽  
S. I. Khartsev ◽  
A. M. Grishin ◽  
Ture Lindbäick
Keyword(s):  
Dielectric Permittivity ◽  
Room Temperature ◽  
Single Phase ◽  
Pulsed Laser ◽  
Dissipation Factor ◽  
Processing Parameters ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
X Ray ◽  
Tan Δ

AbstractWe report on ferroelectric/giant magnetoresistive Na0.5K0.5NbO3/La0.6Sr0.2Mn1.2O3 (NKN/LSMO) heterostructures grown onto LaAlO3 (001) single crystal using KrF pulsed laser ablation of stoichiometric ceramic target. Main processing parameters have been optimized to obtain smooth LSMO template layer, avoid NKN-LSMO interdiffusion, preserve NKN stoichiometry against the lost of volatile potassium and sodium and achieve reasonable reliability of NKN film performance. X-ray diffraction θ- 2θ scans and rocking curves evidence for single-phase content and high c-axis orientation both in template LSMO and top NKN layers. Ferroelectric measurements yield remnant polarization Pr of 1.5 [C/cm2 and spontaneous polarization Ps of 7 μC/cm2 at electric field strength of 130 kV/cm. At room temperature, dielectric permittivity ε′ and dissipation factor tan δ have been found to vary from 595 to 555 and 0.046 to 0.029 respectively in the frequency range of 0.4 to 20 kHz. At 10 kHz dielectric permittivity linearly increases from 410 to 650 in the temperature range 77 K to 415 K while the dissipation factor below 320 K does not exceed 3%.

Impedance Spectroscopy Study of LiTaO3 Powder Synthesized via Sol-Gel Method

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Impedance Spectroscopy Study

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.

scholarly journals Equimolar Yttria-Stabilized Zirconia and Samaria-Doped Ceria Solid Solutions

Ceramics ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 343-352 ◽  
Author(s):  
Reginaldo Muccillo ◽  
Daniel de Florio ◽  
Eliana Muccillo
Keyword(s):  
Tetragonal Phase ◽  
Room Temperature ◽  
Single Phase ◽  
Rietveld Analysis ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Stabilized Zirconia ◽  
X Ray ◽  
Ceria Solid Solutions ◽  
Attrition Milling

Compositions of (ZrO2)0.92(Y2O3)0.08 (zirconia: 8 mol % yttria—8YSZ) and (CeO2)0.8(Sm2O3)0.2 (ceria: 20 mol % samaria—SDC20) ceramic powders were prepared by attrition milling to form an equimolar powder mixture, followed by uniaxial and isostatic pressing. The pellets were quenched to room temperature from 1200 °C, 1300 °C, 1400 °C and 1500 °C to freeze the defects configuration attained at those temperatures. X-ray diffraction analyses, performed in all quenched pellets, show the evolution of the two (8YSZ and SDC20) cubic fluorite structural phases to a single phase at 1500 °C, identified by Rietveld analysis as a tetragonal phase. Impedance spectroscopy analyses were carried out in pellets either quenched or slowly cooled from 1500 °C. Heating the quenched pellets to 1000 °C decreases the electrical resistivity while it increases in the slowly cooled pellets; the decrease is ascribed to annealing of defects created by lattice micro-tensions during quenching while the increase to partial destabilization of the tetragonal phase.

scholarly journals Structure and electric properties of cerium substituted SrBi1.8Ce0.2Nb2O9 and SrBi1.8Ce0.2Ta2O9 ceramics

2016 ◽  
Vol 10 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solid State ◽  
Room Temperature ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Lcr Meter ◽  
Curie Temperature Tc

SrBi1.8Ce0.2Nb2O9 (SBCN) and SrBi1.8Ce0.2Ta2O9 (SBCT) powders were prepared via solid-state reaction method. X-ray diffraction analysis reveals that the SBCN and SBCT powders have the single phase orthorhom-bic Aurivillius structure at room temperature. The contribution of Raman scattering and FTIR spectroscopy of these samples were relatively smooth and resemble each other. The calcined powders were uniaxially pressed and sintered at 1250?C for 8 h to obtaine dense ceramics. Dielectric constant, loss tangent and AC conductivity of the sintered Ce-doped SrBi2Nb2O9 and SrBi2Ta2O9 ceramics were measured by LCR meter. The Ce-doped SBN (SBCN) ceramics have a higher Curie temperature (TC) and dielectric constant at TC (380?C and ?? ~3510) compared to the Ce-doped SBT (SBCT) ceramics (330?C and ?? ~115) when measured at 100Hz. However, the Ce-doped SBT (SBCT) ceramics have lower conductivity and dielectric loss.

scholarly journals Ferromagnetic Order in the Intermetallic Alloys laNi5-xMgx

2012 ◽  
Vol 29 (1) ◽  
pp. 50
Author(s):  
D.N Ba ◽  
L.T Tai ◽  
N.T Trung ◽  
N.T Huy
Keyword(s):  
Magnetic Properties ◽  
Curie Temperature ◽  
Room Temperature ◽  
Single Phase ◽  
Chemical Doping ◽  
Intermetallic Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ferromagnetic Order ◽  
Diffraction Patterns

The influences of the substitution of Ni with Mg on crystallographic and magnetic properties of the intermetallic alloys LaNi5-xMgx (x ≤ 0.4) were investigated. The X-ray diffraction patterns showed that all samples were of single phase, and the lattice parameters, a and c, decreased slightly upon chemical doping. LaNi5 is well known as an exchange-enhanced Pauli paramagnet. Interestingly, in LaNi5-xMgx, the ferromagnetic order existed even with a small amount of dopants; the Curie temperature reached the value of room temperature for x = 0.2, and enhanced with increasing x.

Synthesis and Luminescence Properties of Chalcopyrite-Type CuAlS2

2006 ◽  
Vol 301 ◽  
pp. 177-180 ◽  
Author(s):  
Yuichiro Kuroki ◽  
Tomoichiro Okamoto ◽  
Masasuke Takata
Keyword(s):  
Diffraction Analysis ◽  
Room Temperature ◽  
Single Phase ◽  
Elevated Temperatures ◽  
Emission Peak ◽  
Maximum Intensity ◽  
X Ray Diffraction ◽  
Ultraviolet Emission ◽  
X Ray ◽  
Copper Aluminum

Copper aluminum disulfide (CuAlS2) powders were synthesized in an evacuated ampoule at elevated temperatures. X-ray diffraction analysis revealed that the powders heated at temperatures higher than 800oC were single-phase CuAlS2. In the cathodoluminescence (CL) spectra measured at room temperature, the powders heated at temperatures higher than 600oC exhibited a visible emission peak at approximately 1.8 eV and a distinct ultraviolet emission peak at 3.45 eV. The powder heated at 700oC showed the maximum intensity of ultraviolet emission which is considered to be associated with excitons.

Properties of Nano-ZnO Films Deposited by RF Magnetron Sputtering for SAW Biosensors

2011 ◽  
Vol 418-420 ◽  
pp. 293-296
Author(s):  
Qiu Yun Fu ◽  
Peng Cheng Yi ◽  
Dong Xiang Zhou ◽  
Wei Luo ◽  
Jian Feng Deng
Keyword(s):  
Magnetron Sputtering ◽  
Deposition Time ◽  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Nano Zno ◽  
Axis Orientation ◽  
X Ray

Abstract. In this article, nano-ZnO films were deposited on SiO2/Si (100) substrates by RF (radio frequency) magnetron sputtering using high purity (99.99%) ZnO target. The effects of deposition time and annealing temperature have been investigated. XRD (X-ray diffraction) and FSEM (Field Emission Scanning Electron Microscopy) were employed to characterize the quality of the films. The results show that the ZnO film with thickness of 600nm annealed at 900°C has higher quality of both C-axis orientation and crystallization. And for the Zone film with thickness of 300nm annealed at 850°C, the quality of both C-axis orientation and crystallization is higher than that annealed at 900°C and 950°C.

Zinc Oxide Nano Walls Synthesized by Chemical Vapor Deposition

2014 ◽  
Vol 608 ◽  
pp. 127-131 ◽  
Author(s):  
Suttinart Noothongkaew ◽  
Supakorn Pukird ◽  
Worasak Sukkabot ◽  
Ki Seok An
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Green Emission ◽  
X Ray Diffraction ◽  
Ultraviolet Emission ◽  
Axis Orientation ◽  
X Ray ◽  
Zno Nanostructure

ZnO nanowalls were synthesized by chemical vapor deposition at temperature of 650 °C for 1 hour on the silicon substrate. The morphologies of samples were characterized by scanning electron microscopy (SEM). The result from X-ray diffraction (XRD) confirmed that the ZnO nanowalls were vertical c-axis orientation. A room temperature Photoluminescence peak at 378 nm is ultraviolet emission (UV) and the broad peak at wavelengths around 450-650 nm is corresponding to the green emission of ZnO nanostructure. This synthesis may be applicable for gas sensor or solar cells.

scholarly journals Study of multiferroic properties of Bi2Fe2WO9 ceramic for device application

2016 ◽  
Vol 06 (03) ◽  
pp. 1650023 ◽  
Author(s):  
Jyoshna Rout ◽  
R. N. P. Choudhary
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Electrical Parameters ◽  
Orthorhombic Crystal ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Universal Power Law ◽  
Phase Compound ◽  
Comprehensive Study

The Bi2Fe2WO9 ceramic was prepared using a standard solid-state reaction technique. Preliminary analysis of X-ray diffraction pattern revealed the formation of single-phase compound with orthorhombic crystal symmetry. The surface morphology of the material captured using scanning electron microscope (SEM) exhibits formation of a densely packed microstructure. Comprehensive study of dielectric properties showed two anomalies at 200[Formula: see text]C and 450[Formula: see text]C: first one may be related to magnetic whereas second one may be related to ferroelectric phase transition. The field dependent magnetic study of the material shows the existence of small remnant magnetization ([Formula: see text]) of 0.052[Formula: see text]em[Formula: see text]/g at room temperature. The existence of magneto-electric (ME) coupling coefficient along with above properties confirms multi-ferroic characteristics of the compound. Selected range temperature and frequency dependent electrical parameters (impedance, modulus, conductivity) of the compound shows that electric properties are correlated to its microstructure. Detailed studies of frequency dependence of ac conductivity suggest that the material obeys Jonscher’s universal power law.

Electronic and Magnetic States of Iron Ions in (Bi1-xSrx)FeO3-y Multiferroic Perovskites

2009 ◽  
Vol 152-153 ◽  
pp. 89-92 ◽  
Author(s):  
V. M. Cherepanov ◽  
V. S. Pokatilov
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Ceramic Technology ◽  
Rhombohedral Structure ◽  
X Ray Diffraction ◽  
Strontium Content ◽  
X Ray ◽  
Similar Dependence ◽  
Magnetic States ◽  
57Fe Isotope

The mixed perovskites (Bi1-xSrx)FeO3-y (x = 0.07, 0.14, 0.25 and 0.50) were studied by 57Fe Mössbauer spectroscopy in the temperature range 87–700 K. The samples were prepared by conventional ceramic technology with 10% 57Fe isotope enrichment. X–ray diffraction measurements showed that the samples were single-phase and had a rhombohedral structure at x = 0.07 and a cubic one at x = 0.14-0.50. As the strontium content x increases, the Neel temperature TN(x) increases from 640 K (x = 0) to 670 K (x = 0.25) and then decreases to 637 K (x = 0.5). The similar dependence on x was found for the hyperfine field values B(x) at T = 87 K. The experimental Mössbauer spectra are satisfactorily described by three to four Fe3+ states with the room temperature isomer shift values in the range 0.17-0.43 mm/s, which correspond to the iron sites with 4, 5 and 6 oxygen neighbours.

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