Structural Properties and Ionic Conductivity of Ce0.8Gd0.2O2 and Ce0.8Sm0.2O2 Thin Films Grown by Pulsed Laser Deposition

Author(s):  
Boscope M. K. Sze ◽  
C. N. Wong ◽  
K. H. Wong

Thin films of Ce0.8Gd0.2O2 and Ce0.8Sm0.2O2 oxide electrolytes have been fabricated by pulsed laser deposition on (100)LaAlO3 substrates at temperature from 300 °C to 700 °C and under 100 mTorr oxygen ambient pressure. The crystal structure, crystallinity and lattice parameters of the as-deposited films are investigated by X-ray diffraction. High quality epitaxial and polycrystalline films are obtained at different growth conditions. We have made impedance measurements on these films in the temperature range from 300 °C to 850 °C. Our results reveal a mark increase in the ionic conductivity of these films in comparison with those of the corresponding bulk materials. The observed enhancements are closely related to the crystallinity of the films. Conductivities of 0.1 S/cm or higher for Ce0.8Gd0.2O2 and Ce0.8Sm0.2O2 are obtained at 500 °C. We have demonstrated that in utilizing these thin films solid oxide fuel cells operating at below 500 °C are possible.

1999 ◽  
Vol 14 (6) ◽  
pp. 2355-2358 ◽  
Author(s):  
M. H. Corbett ◽  
G. Catalan ◽  
R. M. Bowman ◽  
J. M. Gregg

Pulsed laser deposition has been used to make two sets of lead magnesium niobate thin films grown on single-crystal h100j MgO substrates. One set was fabricated using a perovskite-rich target while the other used a pyrochlore-rich target. It was found that the growth conditions required to produce almost 100% perovskite Pb(Mg1/3Nb2/3)O3 (PMN) films were largely independent of target crystallography. Films were characterized crystallographically using x-ray diffraction and plan view transmission electron microscopy, chemically using energy dispersive x-ray analysis, and electrically by fabricating a planar thin film capacitor structure and monitoring capacitance as a function of temperature. All characterization techniques indicated that perovskite PMN thin films had been successfully fabricated.


2002 ◽  
Vol 720 ◽  
Author(s):  
Costas G. Fountzoulas ◽  
Daniel M. Potrepka ◽  
Steven C. Tidrow

AbstractFerroelectrics are multicomponent materials with a wealth of interesting and useful properties, such as piezoelectricity. The dielectric constant of the BSTO ferroelectrics can be changed by applying an electric field. Variable dielectric constant results in a change in phase velocity in the device allowing it to be tuned in real time for a particular application. The microstructure of the film influences the electronic properties which in turn influences the performance of the film. Ba0.6Sr0.4Ti1-y(A 3+, B5+)yO3 thin films, of nominal thickness of 0.65 μm, were synthesized initially at substrate temperatures of 400°C, and subsequently annealed to 750°C, on LaAlO3 (100) substrates, previously coated with LaSrCoO conductive buffer layer, using the pulsed laser deposition technique. The microstructural and physical characteristics of the postannealed thin films have been studied using x-ray diffraction, scanning electron microscopy, and nano indentation and are reported. Results of capacitance measurements are used to obtain dielectric constant and tunability in the paraelectric (T>Tc) regime.


2010 ◽  
Vol 123-125 ◽  
pp. 375-378 ◽  
Author(s):  
Ram Prakash ◽  
Shalendra Kumar ◽  
Chan Gyu Lee ◽  
S.K. Sharma ◽  
Marcelo Knobel ◽  
...  

Ce1-xFexO2 (x=0, 0.01, 0.03 and 0.0 5) thin films were grown by pulsed laser deposition technique on Si and LaAlO3 (LAO) substrates. These films were deposited in vacuum and 200 mTorr oxygen partial pressure for both the substrates. These films were characterized by x-ray diffraction XRD and Raman spectroscopy measurements. XRD results reveal that these films are single phase. Raman results show F2g mode at ~466 cm-1 and defect peak at 489 cm-1 for film that deposited on LAO substrates, full width at half maximum (FWHM) is increasing with Fe doping for films deposited on both the substrates.


2009 ◽  
Vol 67 ◽  
pp. 65-70 ◽  
Author(s):  
Gaurav Shukla ◽  
Alika K. Khare

TiO2 is a widely studied material for many important applications in areas such as environmental purification, photocatalyst, gas sensors, cancer therapy and high effect solar cell. However, investigations demonstrated that the properties and applications of titanium oxide films depend upon the nature of the crystalline phases present in the films, i.e. anatase and rutile phases. We report on the pulsed laser deposition of high quality TiO2 thin films. Pulsed Laser deposition of TiO2 thin films were performed in different ambient viz. oxygen, argon and vacuum, using a second harmonic of Nd:YAG laser of 6 ns pulse width. These deposited films of TiO2 were further annealed for 5hrs in air at different temperatures. TiO2 thin films were characterized using x-ray diffraction, SEM, photoluminescence, transmittance and reflectance. We observed effect of annealing over structural, morphological and optical properties of TiO2 thin films. The anatase phase of as-deposited TiO2 thin films is found to change into rutile phase with increased annealing temperature. Increase in crystalline behaviour of thin films with post-annealing temperature is also observed. Surface morphology of TiO2 thin films is dependent upon ambient pressure and post- annealing temperature. TiO2 thin films are found to be optically transparent with very low reflectivity hence will be suitable for antireflection coating applications.


2021 ◽  
Vol 19 (10) ◽  
pp. 34-40
Author(s):  
B.Y. Taher ◽  
A.S. Ahmed ◽  
Hassan J. Alatta

In this study, CdO2 (1-X) AlX thin films were prepared by pulsed-laser deposition. The X-ray diffraction patterns reveal that the films were polycrystalline with a cubic structure, and the composition of the material changed from CdO at the target to CdO2 in the deposited thin films. The intensity of the diffraction peak (or the texture factor) decreases with increasing hkl and has a maximum value for the (111) plane, the interplanar distance and diffraction angle has a high deviation from the standard value for the (111) plane and. This deviation is affected by doping concentration and shows its highest deviation at a doping concentration of 0.1 wt.% for the (111) and (200), and the 0.3 and 0.5 wt.% for the (210) and (220) planes, respectively. The crystalline size take a less value at plane has a high texture factor that is (111) plane and decreases with increase the doping concentration.


2012 ◽  
Vol 45 (1) ◽  
pp. 333-336 ◽  
Author(s):  
A. Evans ◽  
S. Karalic ◽  
J. Martynczuk ◽  
M. Prestat ◽  
R. Tolke ◽  
...  

2013 ◽  
Vol 710 ◽  
pp. 25-28 ◽  
Author(s):  
Xiao Qiang Kou ◽  
Ji Ming Bian ◽  
Zhi Kun Zhang

Vanadium dioxide (VO2) films were grown on c-and m-plane sapphire substrates by pulsed laser deposition (PLD) technique with VO2ceramic target. The VO2films with preferred growth orientation and uniform dense distribution have been achieved on both substrates, as confirmed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The terahertz (THz) transmission properties of VO2thin films were studied by terahertz time-domain spectroscopy (THz-TDS). The results indicate that the THz transmission properties of VO2films are strongly influenced by the sapphire substrate orientation, suggesting that VO2films are ideal material candidates for THz modulation.


2005 ◽  
Vol 19 (01n03) ◽  
pp. 533-535
Author(s):  
J. H. HAO ◽  
J. GAO

We have developed a process to grow SrTiO 3 ( STO ) thin films showing single (110) orientation directly on Si by means of pulsed laser deposition technique. The growth of STO films directly on Si has been described. The crystallinity of the grown STO films was characterized by X-ray diffraction analysis of θ-2θ scan and rocking curve. Our results may be of interest for better understanding of the growth based on the perovskite oxide thin films on silicon materials.


1997 ◽  
Vol 472 ◽  
Author(s):  
M.A. El Khakani ◽  
M. Chaker

ABSTRACTReactive pulsed laser deposition has been used to deposit IrO2 thin films on both SiO2 and fused quartz substrates, by ablating a metal iridium target in oxygen atmosphere. At a KrF laser intensity of about 1.7 × 109 W/cm2, IrO2 films were deposited at substrate deposition temperatures ranging from room-temperature to 700 °C under an optimum oxygen ambient pressure of 200 mTorr. The structure, morphology, electrical resistivity and optical transmission of the deposited films were characterized as a function of their deposition temperature (Td). High quality IrO2 films are obtained in the 400–600 °C deposition temperature range. They are polycrystalline with preferred orientations, depending on the substrate, and show a dense granular morphology. At a Td as low as 400 °C, highly conductive IrO2 films with room-temperature resistivities as low as (42±6) μΩ cm are obtained. Over the 300–600 °C Td range, the IrO2 films were found to exhibit a maximum optical transmission at 450 °C (∼ 45 % at 500 nm for 80 nm-thick films).


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