Synthesis and Characterization of PbO Films Grown by Pulsed Laser Deposition.

1991 ◽  
Vol 235 ◽  
Author(s):  
J. S. Zabinski ◽  
M. S. Donley ◽  
V. J. Dyhouse ◽  
R. Moore ◽  
N. T. McDevitt

ABSTRACTLead monoxide (PbO) is a potential solid lubricant for use at elevated temperatures in oxidizing environments. The objective of this research was to grow thin films of PbO by Pulsed Laser Deposition (PLD). Film stoichiometry, crystallinity, and chemistry were adjusted by varying substrate temperature and O2 partial pressure during deposition and the effects of changes in film properties on friction coefficients and wear lives were investigated. Chemistry and crystallinity were evaluated using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and glancing angle X-ray diffraction (XRD). Friction coefficients and wear lives were measured in dry nitrogen and at room temperature using a ball-on-flat tribometer. Films deposited at room temperature retained the crystal structure of the target material, but were oxygen deficient. The O/Pb ratio was increased by raising the O2 partial pressure and by increasing the substrate temperature during deposition; the crystal structure and orientation changed with stoichiometry. Friction coefficients ranged from 0.20 – 0.45 and the wear lives were typically less than those obtained from MoS2 films.

1991 ◽  
Vol 236 ◽  
Author(s):  
J.S. Zabinski ◽  
M.S. Donley ◽  
V.J. Dyhouse ◽  
R. Moore ◽  
N.T. McDevitt

AbstractLead monoxide (PbO) is a potential solid lubricant for use at elevated temperatures in oxidizing environments. The objective of this research was to grow thin films of PbO by Pulsed Laser Deposition (PLD). Film stoichiometry, crystallinity, and chemistry were adjusted by varying substrate temperature and O2 partial pressure during deposition and the effects of changes in film properties on friction coefficients and wear lives were investigated. Chemistry and crystallinity were evaluated using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and glancing angle X-ray diffraction (XRD). Friction coefficients and wear lives were measured in dry nitrogen and at room temperature using a ball-on-flat tribometer. Films deposited at room temperature retained the crystal structure of the target material, but were oxygen deficient. The O/Pb ratio was increased by raising the O2 partial pressure and by increasing the substrate temperature during deposition; the crystal structure and orientation changed with stoichiometry. Friction coefficients ranged from 0.20 - 0.45 and the wear lives were typically less than those obtained from MoS2 films.


2001 ◽  
Vol 697 ◽  
Author(s):  
A.R. Phani ◽  
J.E. Krzanowski ◽  
J.J. Nainaparampil

AbstractTitanium carbide films have been deposited using a hybrid magnetron sputtering/ pulsed laser deposition technique. One set of films was deposited at substrate temperatures ranging from room temperature to 600oC with no substrate bias, and a second set was deposited at 400°C bias voltages up to -150V. X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopy were employed for structural and compositional characterization of the films, and nano-indentation hardness testing and pin-on-disc wear tests were used to evaluate the mechanical and tribological properties. All the TiC films deposited without substrate bias were highly crystalline. The films deposited with bias had significantly reduced crystallinity and non-stoichiometric film compositions. The hardness of the TiC films increased with substrate temperature from 8 GPa at room temperature to 18 GPa at 600oC, whereas the biased films had a maximum hardness of 12 GPa. The wear test data showed significantly lower friction and longer wear life for the -150V biased film.


2014 ◽  
Vol 912-914 ◽  
pp. 325-328 ◽  
Author(s):  
Ji Ming Bian ◽  
Li Hua Miao ◽  
Shu Kuo Zhao

VO2films were grown on sapphire substrates by pulsed laser deposition (PLD), and the structural and optical properties of as-grown films were investigated by X-ray diffraction (XRD), field effect scanning electron microscopy (FESEM), photoluminescence (PL), and optical-transmission measurements. The oxygen partial pressure in the growth chamber was found to be the key factor deciding the microstructure and properties of as-deposited VO2films, and its effects and corresponding mechanism were investigated systemically. Results indicated that dense and uniform VO2films with smooth surface were achieved by PLD under optimized oxygen partial pressure. Strong blue emission peaks were observed in room temperature photoluminescence (PL) spectra. Excellent selective optical-transmission of the VO2thin films from 200~3000 nm were also recorded at room temperature.


2011 ◽  
Vol 383-390 ◽  
pp. 6289-6292
Author(s):  
Jian Ting He ◽  
Bo Xue Tan ◽  
Qin Qin Wei ◽  
Yuan Bin Su ◽  
Shu Lian Yang

ZnO thin films were deposited on n-Si (111) substrates at various oxygen partial pressures by pulsed laser deposition (PLD). X-ray diffraction (XRD), scanning electron microscopy (SEM) were used to analyze the influence of the oxygen partial pressure on the crystallization and morphology of the ZnO thin films. An optimal crystallized ZnO thin film was observed at the oxygen partial pressure of 6.5Pa. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface components and distribution status of various elments in ZnO thin films. It was found that ZnO thin films were grown in Zn-rich state.


2010 ◽  
Vol 25 (10) ◽  
pp. 1936-1942 ◽  
Author(s):  
Deuk Ho Yeon ◽  
Bhaskar Chandra Mohanty ◽  
Yeon Hwa Jo ◽  
Yong Soo Cho

An effective way to prepare a robust CuInSe2 (CIS) target for subsequent vapor depositions of thin films is suggested in this work. The technique involves addition of excess Se to presynthesized CIS powder followed by cold pressing and sintering at a temperature as low as 300 °C. Phase-pure chalcopyrite CIS films were prepared at a substrate temperature of 300 °C from targets that contained different amounts of excess Se. The average size of particulates, typical of the pulsed laser deposition process, and their surface coverage decreased with increasing Se content up to 50 wt% in the targets. Films grown from the target with 50 wt% excess Se exhibited a hole concentration of ˜3 × 1019 cm−3 and a Hall mobility of ˜2 cm2/Vs. With the decrease of substrate temperature to room temperature, the resistivity increased from 1.1 × 10−1 to ˜7.5 × 108 Ω·cm, which is attributed to the potential contributions of Se interstitials, CuIn, and VIn defects.


2012 ◽  
Vol 26 (30) ◽  
pp. 1250161 ◽  
Author(s):  
D. ZHANG ◽  
C. Z. WANG ◽  
F. X. ZHANG

Zinc oxide films were deposited on silicon substrates by reactive pulsed laser deposition of zinc target. The effect of substrate temperatures on the crystal and band edge luminescence was studied using X-ray diffraction, scanning electron microscopy and Raman spectra. All the films deposited in the substrate temperatures range from room temperature to 600°C exhibited strong c-axis orientation. The preferred orientation of crystal changed with substrate temperature increase, due to the preferential nucleation at lower temperatures and surface diffusion at higher temperatures. The detailed micro-structural analysis indicated a tensile stress in all the films using X-ray diffraction and Raman spectra. It is interesting that the film deposited at 350°C, which exhibited best crystallinity quality in the X-ray diffraction, rocking curve and the best stoichiometry, less defects in Raman spectra, does not show the most intense UV emission and weakest visible emission. The most intense UV emission was exhibited in the films deposited at 500°C which had the equiaxed grain size.


2005 ◽  
Vol 108-109 ◽  
pp. 723-728 ◽  
Author(s):  
Mathias Kappa ◽  
Markus Ratzke ◽  
Jürgen Reif

Hafnium oxide films were prepared by Pulsed Laser Deposition (PLD). The influence of laser wavelength (fundamental, second and third harmonic of a Nd:YAG laser), used for evaporation, and substrate temperature on the film morphology, chemical structure and interfacial quality were investigated yielding the following results: While the laser wavelength exhibits minor influence on layer structure, the substrate temperature plays a critical role regarding morphological and chemical structure of the produced hafnium oxide / silicon stacks. Atomic Force Microscopy (AFM) images show a clear transition from smooth layers consisting of small area crystallites to very rough surfaces characterized by large craters and regular, plane features when the growth temperature was increased. These facts suggest a chemical instability which is confirmed by X-ray Photoelectron Spectroscopy (XPS). Investigations of the hafnium and silicon core level spectra indicate the occurrence of silicon dioxide and hafnium silicide in the case the samples were produced at elevated temperatures.


1994 ◽  
Vol 361 ◽  
Author(s):  
Y. Liu ◽  
C.W. Ong ◽  
P.W. Chan ◽  
C.L. Choy

ABSTRACTStrontium barium niobate Sr0.55Ba0.45Nb2O6 thin films were prepared on Si (111) substrates by pulsed laser deposition (PLD). The film composition was determined as a function of the fluence φ and wavelength λ of the laser beam, the oxygen ambient pressure Po2 and the substrate temperature Ts. The results show that the film composition is very close to that of the target, and is almost independent of φ from 1 to 8 J cm−2, λ = 355, 532 and 1064 nm, Po2 from 0 to 150 mTorr, and Ts from 25 to 700°C. These results suggest that PLD is excellent for preparing SBN films with compositions congruent to that of the target. The x-ray diffraction data show that all the samples deposited at room temperature are amorphous. The x-ray diffraction results also indicate that the samples deposited at 700°C have a tungsten-bronze-(TB-) type structure with preferred crystallite orientation, while the room-temperature-deposited samples after annealing at 800°C for 30 minutes are polycrystalline and have random crystallite orientation.


2010 ◽  
Vol 1267 ◽  
Author(s):  
Evan Lyle Thomas ◽  
Xueyan Song ◽  
Yonggao Yan ◽  
Joshua Martin ◽  
Winnie Wong-Ng ◽  
...  

AbstractThe influence of incorporating nanoparticulate additions into Ca3Co4O9 (CCO) thin films prepared by pulsed laser deposition using composite targets of CCO and CCO + 3wt% BaZrO3 (BZO) on Si and LaAlO3 substrates is investigated. X-ray data and high-resolution scanning electron microscopy reveal preferred c-axis orientation of the films deposited on Si substrates with the formation of nanoparticles between ∼ 10 – 50 nm. Preliminary thermoelectric behavior shows an enhancement of the power factor α2/ρ at room temperature. The microstructure and thermoelectric behavior of the CCO films are compared to the BZO-doped films.


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