Ionic Conductivities of Doped CeO2 Thin Films as Related to Their Microstructure

ABSTRACTThin films of 4% Y2O3 doped CeO2/Pd film/(001)LaA103 with a very low pinhole density were successfully prepared using electron-beam deposition technique. The microstructure of the films was characterized by x-ray diffraction and the electrical properties were studied as a function of temperature with AC impedance spectroscopy. A brick layer model was adopted to correlate the electrical properties to the microstructure of the films, which can be simplified as either a series or a parallel equivalent circuit associated with either a fine grain or a columnar grain structure, respectively. The conductivities of the films fell between the conductivities derived from the two circuit models, suggesting that the films are of a mixed fine grain and columnar grain structure. The measured dielectric constants of the films were found smaller than that of the bulk.

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Grain boundary conductivity and microstructure study of 4% Y2O3 doped CeO2 thin films

MRS Proceedings ◽

10.1557/proc-453-555 ◽

1996 ◽

Vol 453 ◽

Cited By ~ 4

Author(s):

Chunyan Tian ◽

Siu-Wai Chan

Keyword(s):

Thin Films ◽

Grain Boundary ◽

Complex Impedance ◽

Preexponential Factor ◽

X Ray Diffraction ◽

Ac Impedance Spectroscopy ◽

Boundary Conductivity ◽

Transmission Electron ◽

Brick Layer Model ◽

Beam Deposition

AbstractThe thin films of 4% Y2O3 doped CeO2 have been deposited on different substrates of Pd film/(001) LaAlO3, Pd film/r-cut sapphire, and Pd film/Quartz using an e-beam deposition technique. The microstructures and electrical properties of the films were investigated by means of x-ray diffraction, transmission electron microscopy, and ac impedance spectroscopy. Both textured and polycrystalline films were produced on different substrates. A brick layer model was adopted to correlate the micro structure and electrical property of the films. Only the grain boundary arc was observed in the film complex impedance plots. The conductivities of the films were similar to the conductivity of 6% Y2O3 doped CeO2 bulk grain boundary because of lower preexponential factor, although the activation energies were smaller than that of bulk grain boundary. The resistive gram boundaries were found to dominate the conductivities of the films.

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Microstructure and properties of PbZr0.6Ti0.4O3 and PbZrO3 thin films deposited on template layers

Journal of Materials Research ◽

10.1557/jmr.2000.0283 ◽

2000 ◽

Vol 15 (9) ◽

pp. 1962-1971 ◽

Cited By ~ 9

Author(s):

R. E. Koritala ◽

M. T. Lanagan ◽

N. Chen ◽

G. R. Bai ◽

Y. Huang ◽

...

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Chemical Vapor ◽

Dielectric Constants ◽

Breakdown Field ◽

X Ray Diffraction ◽

Electrical Measurements ◽

X Ray ◽

Si Substrates ◽

Antiferroelectric Phase

Polycrystalline Pb(ZrxTi1−x)O3 thin films with x = 0.6 and 1.0 were deposited at low temperatures (450–525 °C) on (111)Pt/Ti/SiO2/Si substrates by metalorganic chemical vapor deposition. The films were characterized by x-ray diffraction, electron microscopy, and electrical measurements. The texture of the films could be improved by using one of two template layers: PbTiO3 or TiO2. Electrical properties, including dielectric constants, loss tangents, polarization, coercive field, and breakdown field, were also examined. PbZrO3 films on Pt/Ti/SiO2/Si with a pseudocubic (110) orientation exhibited an electric-field-induced transformation from the antiferroelectric phase to the ferroelectric phase. The effect of varying processing conditions on the microstructure and electrical properties of the films is discussed.

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TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100167561 ◽

1996 ◽

Vol 54 ◽

pp. 1020-1021

Author(s):

F. Ma ◽

S. Vivekanand ◽

K. Barmak ◽

C. Michaelsen

Keyword(s):

Thin Films ◽

Solid State ◽

Stoichiometric Composition ◽

Analytical Electron Microscopy ◽

Grain Structure ◽

Solid State Reactions ◽

Multilayer Thin Films ◽

X Ray Diffraction ◽

X Ray ◽

Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

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X- ray diffraction and dielectric properties of PbSe thin films

Iraqi Journal of Physics (IJP) ◽

10.30723/ijp.v15i34.115 ◽

2019 ◽

Vol 15 (34) ◽

pp. 1-14

Author(s):

Bushra A. Hasan

Keyword(s):

Thin Films ◽

Thermal Activation ◽

Thermal Evaporation ◽

Thermal Activation Energy ◽

Dielectric Constants ◽

Conductivity Measurements ◽

X Ray Diffraction ◽

Thermal Evaporation Method ◽

X Ray ◽

Glass Substrates

Lead selenide PbSe thin films of different thicknesses (300, 500, and 700 nm) were deposited under vacuum using thermal evaporation method on glass substrates. X-ray diffraction measurements showed that increasing of thickness lead to well crystallize the prepared samples, such that the crystallite size increases while the dislocation density decreases with thickness increasing. A.C conductivity, dielectric constants, and loss tangent are studied as function to thickness, frequency (10kHz-10MHz) and temperatures (293K-493K). The conductivity measurements confirm confirmed that hopping is the mechanism responsible for the conduction process. Increasing of thickness decreases the thermal activation energy estimated from Arhinus equation is found to decrease with thickness increasing. The increase of thickness lead to reduce the polarizability α while the increasing of temperature lead to increase α.

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Crystallization of Zn-rich and P-rich amorphous Zn3P2 thin films

Canadian Journal of Physics ◽

10.1139/p88-060 ◽

1988 ◽

Vol 66 (5) ◽

pp. 373-375 ◽

Cited By ~ 4

Author(s):

C. J. Arsenault ◽

D. E. Brodie

Keyword(s):

Thin Film ◽

Thin Films ◽

Activation Energy ◽

Electrical Properties ◽

Structural Properties ◽

Crystallization Process ◽

X Ray Diffraction ◽

Electrical Measurements ◽

Conductivity Activation Energy ◽

X Ray

Zn-rich and P-rich amorphous Zn3P2 thin films were prepared by co-evaporation of the excess element during the normal Zn3P2 deposition. X-ray diffraction techniques were used to investigate the structural properties and the crystallization process. Agglomeration of the excess element within the as-made amorphous Zn3P2 thin film accounted for the structural properties observed after annealing the sample. Electrical measurements showed that excess Zn reduces the conductivity activation energy and increases the conductivity, while excess P up to 15 at.% does not alter the electrical properties significantly.

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Crystal Structure, Lattice Strain, Morphology, and Electrical Properties of SnO2 Nanoparticles Induced by Low Calcination Temperature

Advances in Materials Science and Engineering ◽

10.1155/2020/3852421 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Panya Khaenamkaew ◽

Dhonluck Manop ◽

Chaileok Tanghengjaroen ◽

Worasit Palakawong Na Ayuthaya

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Calcination Temperature ◽

Tin Dioxide ◽

Lattice Strain ◽

Dielectric Constants ◽

Precipitation Method ◽

Calcination Temperatures ◽

Sensing Applications ◽

Crystallite Sizes

The electrical properties of tin dioxide (SnO2) nanoparticles induced by low calcination temperature were systematically investigated for gas sensing applications. The precipitation method was used to prepare SnO2 powders, while the sol-gel method was adopted to prepare SnO2 thin films at different calcination temperatures. The characterization was done by X-ray diffraction, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The samples were perfectly matched with the rutile tetragonal structure. The average crystallite sizes of SnO2 powders were 45 ± 2, 50 ± 2, 62 ± 2, and 65 ± 2 nm at calcination temperatures of 300, 350, 400, and 450°C, respectively. SEM images and AFM topographies showed an increase in particle size and roughness with the rise in calcination temperature. The dielectric constant decreased with the increase in the frequency of the applied signals but increased on increasing calcination temperature. By using the UV-Vis spectrum, the direct energy bandgaps of SnO2 thin films were found as 4.85, 4.80, 4.75, and 4.10 eV for 300, 350, 400, and 450°C, respectively. Low calcination temperature as 300°C allows smaller crystallite sizes and lower dielectric constants but increases the surface roughness of SnO2, while lattice strain remains independent. Thus, low calcination temperatures of SnO2 are promising for electronic devices like gas sensors.

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Effect Of Fluorine Doping On The Structural, Optical And Electrical Properties Of Spin Coated Tin Oxide Thin Films For Solar Cells Application

10.36293/sfj.2019.0002 ◽

2019 ◽

Keyword(s):

Thin Films ◽

Solar Cells ◽

Electrical Properties ◽

Tin Oxide ◽

Transparent Conducting Oxide ◽

Optical And Electrical Properties ◽

Fluorine Doping ◽

X Ray Diffraction ◽

X Ray ◽

Transparent Conducting

Transparent conducting oxide (TCO) thin films are materials of significance for their applications in optoelectronics and sun powered cells. Fluorine-doped tin oxide (FTO) is an elective material in the advancement of TCO films. This paper reports the impact of fluorine doping on structural, optical and electrical properties of tin oxide thin films for solar cells application. The sol-gel was prepared from anhydrous stannous chloride, SnCl2 as an originator, 2-methoxyethanol as a solvent, di-ethanolamine as a preservative and ammonium fluoride as the dopant source. FTO precursor solution was formulated to obtain 0, 5, 10, 15 and 20 % doping concentration and deposited on glass substrates by means of spin coater at the rate of 2000 rpm for 40 seconds. After pre-heated at 200 oC, the samples were annealed at 600 oC for 2 h. The structural, optical and electrical characteristics of prepared films were characterized using X-ray diffraction (XRD) analysis, UV-visible spectroscopy and electrical measurement. X-ray diffraction (XRD) investigation of the films demonstrated that the films were polycrystalline in nature with tetragonal-cassiterite structure with most extraordinary pinnacle having a grain size of 17.01 nm. Doping with fluorine decreases the crystallite size. There was increment in the absorbance of the film with increasing wavelength and the transmittance was basically reduced with increasing fluorine doping in the visible region. The energy band gaps were in the range of 4.106-4.121 eV. The sheet resistance were observed to decrease as the doping percentage of fluorine increased with exception at higher doping of 15 and 20 %. In view of these outcomes, FTO thin films prepared could have useful application in transparent conducting oxide electrode in solar cell.

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An Investigation of the Electrical Behavior of Thermally Sprayed Aluminum Oxide

Thermal Spray 1996: Proceedings from the National Thermal Spray Conference ◽

10.31399/asm.cp.itsc1996p0793 ◽

1996 ◽

Author(s):

C.J. Swindeman ◽

R.D. Seals ◽

W.P. Murray ◽

M.H. Cooper ◽

R.L. White

Keyword(s):

Electrical Properties ◽

Aluminum Oxide ◽

Dielectric Constants ◽

Electrical Behavior ◽

X Ray Diffraction ◽

Heating And Cooling ◽

Thermally Sprayed Aluminum ◽

Plasma Sprayed ◽

And Control ◽

Steel Substrates

Abstract Electrical properties of plasma-sprayed aluminum oxide coatings were measured at temperatures up to 600 °C. High purity (>99.5 wt% pure Al2O3) alumina powders were plasma-sprayed on stainless steel substrates over a range of power levels, using two gun configurations designed to attain different spray velocities. Key electrical properties were measured to evaluate the resultant coatings as potential insulating materials for electrostatic chucks (ESCs) being developed for semiconductor manufacturing. Electrical resistivity of all coatings was measured under vacuum upon heating and cooling over a temperature range of 20 to 600 °C. Dielectric constants were also measured under the same test conditions. X-ray diffraction was performed to examine phase formation in the coatings. Results show the importance of powder composition and careful selection and control of spray conditions for optimizing electrical behavior in plasma-sprayed aluminum oxide, and point to the need for further studies to characterize the relationship between high temperature electrical properties, measured plasma-spray variables, and specific microstructural and compositional coating features.

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