Study of Nanostructure Inclusion Effects on the Thermoelectric Behavior of Ca3Co4O9 Thin Films Grown by Pulsed Laser Deposition

2010 ◽  
Vol 1267 ◽  
Author(s):  
Evan Lyle Thomas ◽  
Xueyan Song ◽  
Yonggao Yan ◽  
Joshua Martin ◽  
Winnie Wong-Ng ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Axis Orientation ◽  
X Ray ◽  
Si Substrates ◽  
Factor Α ◽  
Scanning Electron

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.

Electrical Properties of ZnO Thin Films Deposited by Pulsed Laser Deposition.

2004 ◽  
Vol 829 ◽  
Author(s):  
S. P. Heluani ◽  
G. Simonelli ◽  
M. Villafuerte ◽  
G. Juarez ◽  
A. Tirpak ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Zno Thin Films ◽  
Axis Orientation ◽  
Si Substrates ◽  
N2 Atmosphere ◽  
Doping Effects ◽  
High O2

ABSTRACTStructural and electronic transport properties of polycrystalline ZnO thin films, prepared by pulsed laser deposition, have been investigated. The films were deposited on glass and Si3N4/Si substrates using O2 and N2 atmospheres. X-ray analysis revealed preferential c-axis orientation perpendicular to the sample substrate. Films deposited under relatively high O2 pressure were highly resistive. However, the conductivity σ increased while the films were irradiated with ultraviolet light, showing an Arrhenius (In σ ∝ T-1) dependence as a function of temperature. The ZnO film deposited in N2 atmosphere exhibited at room temperature a resistivity ∼ 1 Ω cm, and a sheet carrier concentration ∼ 5 1012 cm-2. The variation of the conductivity with temperature, in the range 60 – 150 K, follows a In σ ∝ T-1/4 dependence characteristic of variable range hopping. An analysis of the experimental results of conductivity as a function of temperature, in terms of possible doping effects, as well as conduction mechanisms is presented.

ZrC Thin Films Grown by Pulsed Laser Deposition

2003 ◽  
Vol 780 ◽  
Author(s):  
V. Craciun ◽  
D. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Surface Region ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Crystalline Films

AbstractZrC thin films were grown on Si substrates by the pulsed laser deposition (PLD) technique. X- ray photoelectron spectroscopy, x-ray diffraction and reflectivity, variable angle spectroscopic ellipsometry, and four point probe measurements were used to investigate the composition, density, thickness, surface morphology, optical and electrical properties of the grown structures. It has been found that crystalline films could be grown only by using fluences above 6 J/cm2 and substrate temperatures in excess of 500 °C. For a fluence of 10 J/cm2 and a substrate temperature of 700 °C, highly (100)-textured ZrC films exhibiting a cubic structure (a=0.469 nm) and a density of 6.7 g/cm3 were deposited. The use of a low-pressure atmosphere of C2H2 had a beneficial effect on crystallinity and stoichiometry of the films. All films contained high levels of oxygen contamination, especially in the surface region, because of the rather reactive nature of Zr atoms.

Strontium Barium Niobate Thin Films Prepared by Pulsed Laser Deposition

1994 ◽  
Vol 361 ◽  
Author(s):  
Y. Liu ◽  
C.W. Ong ◽  
P.W. Chan ◽  
C.L. Choy
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Crystallite Orientation ◽  
Strontium Barium ◽  
Film Composition ◽  
X Ray

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.

Room-temperature Ferromagnetic Zn0.95Co0.05O Diluted Magnetic Semiconducting Thin Films by Pulsed Laser Deposition

2006 ◽  
Vol 928 ◽  
Author(s):  
Yuebin Zhang ◽  
Qing Liu ◽  
Thirumany Sritharan ◽  
Chee-Lip Gan ◽  
Sean Li
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray ◽  
Doped Zno ◽  
Diluted Magnetic ◽  
Co Doped

ABSTRACTCo-doped ZnO thin films with room-temperature ferromagnetism have been successfully synthesized on (001) Si substrates at 450 °C by pulsed-laser deposition using a Zn0.95Co0.05O ceramic target. Their microstructural properties are carefully studied using atomic force microscopy, x-ray diffraction and high-resolution transmission electron microscopy. The oxidation state of Co and the ratio of Co/Zn are examined by x-ray photoelectron spectroscopy, and magnetic measurements are performed using SQUID. The results show that a single-phase crystalline Co-doped ZnO film was grown with (002) preferential orientation and some edge dislocations formed during the film growth. The origin of room-temperature ferromagnetism is explored. The presence of nanoclusters of any magnetic phase can be ruled out. The dislocations, coupled with oxygen vacancy, may contribute to the ferromagnetic properties in the much diluted magnetic semiconductor.

Control of a-Axis and c-AXIS Orientation of the YBa2Cu3O7−x Thin Films by Pulsed Laser Deposition

1992 ◽  
Vol 275 ◽  
Author(s):  
Gun Yong Sung ◽  
Jeong Dae Suh ◽  
Kwang Yong Kang ◽  
Jeong Yong Lee
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Ybco Film ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
X Ray ◽  
Layer Structures

ABSTRACTWe have investigated the effect of substrate temperatures ranging from 680 °C to 800 °C on the orientation of pulsed laser deposited YBa2Cu3O7−x.(YBCO) thin films on (100) LaAlO3 substrates. X-ray diffraction studies indicate that there is a progressive change in the dominant orientation of the films from c-axis oriented (c-axis perpendicular to the substrate surface) to a-axis oriented (a-axis perpendicular to the substrate surface) grown as the substrate temperature is lowered. Two YBCO bilayers, which are the a-axis oriented YBCO film on the top of c-axis oriented YBCO film (a/c) bilayer and c-axis oriented YBCO film on the top of a-axis oriented YBCO film (c/a) bilayer, have been grown by in situ two step pulsed laser deposition and were characterized by scanning electron microscopy (SEM), Rutherford backscattering (RBS) spectrum, x-ray diffraction (XRD), and Tc measurements. Through SEM and XRD studies, double layer structures of the a/c and c/a bilayers were confirmed indirectly.

Aluminum Nitride Thin Films Grown by Plasma-Assisted Pulsed Laser Deposition on Si Substrates

1997 ◽  
Vol 468 ◽  
Author(s):  
M. Okamoto ◽  
T. Ogawa ◽  
Y. Mori ◽  
T. Sasaki
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Atomic Ratio ◽  
Laser Deposition ◽  
X Ray ◽  
Si Substrates ◽  
High Laser ◽  
High Laser Energy

ABSTRACTThe smooth and highly oriented AlN films were obtained using pulsed laser deposition from sintered AlN target in a nitrogen ambient. The XRD investigation revealed that highly oriented AlN thin films along the c-axis (AlN (0002)) normal to the substrate were obtained both on Si(111) and on Si(100) substrates. The (0002) x-ray peak width became narrower with increasing substrate temperature. The CL investigation showed that AlN films at high laser energy density (Ed) indicated CL peak at shorter wavelength (306nm) than that at low Ed (394nm). N/Al atomic ratio in AlN films grown at high Ed also increased as comparison with the films grown at low Ed.

Processing by Pulsed Laser Deposition and Structural, Morphological and Chemical Characterization of Bi-Pb-Sr-Ca-Cu-O and Bi-Pb-Sb-Sr-Ca-Cu-O Thin Films

2010 ◽  
Vol 75 ◽  
pp. 202-207
Author(s):  
Victor Ríos ◽  
Elvia Díaz-Valdés ◽  
Jorge Ricardo Aguilar ◽  
T.G. Kryshtab ◽  
Ciro Falcony
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Chemical Characterization ◽  
Laser Deposition ◽  
Nominal Composition ◽  
Deposition Parameters ◽  
The Relationship

Bi-Pb-Sr-Ca-Cu-O (BPSCCO) and Bi-Pb-Sb-Sr-Ca-Cu-O (BPSSCCO) thin films were grown on MgO single crystal substrates by pulsed laser deposition. The deposition was carried out at room temperature during 90 minutes. A Nd:YAG excimer laser ( = 355 nm) with a 2 J/pulse energy density operated at 30 Hz was used. The distance between the target and substrate was kept constant at 4,5 cm. Nominal composition of the targets was Bi1,6Pb0,4Sr2Ca2Cu3O and Bi1,6Pb0,4Sb0,1Sr2Ca2Cu3OSuperconducting targets were prepared following a state solid reaction. As-grown films were annealed at different conditions. As-grown and annealed films were characterized by XRD, FTIR, and SEM. The films were prepared applying an experimental design. The relationship among deposition parameters and their effect on the formation of superconducting Bi-system crystalline phases was studied.

Room-temperature ferromagnetism in (Ga, Mn)N thin films grown by pulsed laser deposition

2004 ◽  
Vol 36 (4-6) ◽  
pp. 403-408 ◽  
Author(s):  
D. O’Mahony ◽  
F. McGee ◽  
M. Venkatesan ◽  
J.G. Lunney ◽  
J.M.D. Coey
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Pulsed Laser ◽  
Laser Deposition

Study of Raman Spectrum of Fe Doped CeO2 Thin Films Grown by Pulsed Laser Deposition

2010 ◽  
Vol 123-125 ◽  
pp. 375-378 ◽  
Author(s):  
Ram Prakash ◽  
Shalendra Kumar ◽  
Chan Gyu Lee ◽  
S.K. Sharma ◽  
Marcelo Knobel ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Single Phase ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Fe Doping ◽  
Full Width ◽  
Deposition Technique ◽  
X Ray Diffraction ◽  
X Ray

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.

Fabrication of Ni–Al thin films by the pulsed laser deposition technique

1992 ◽  
Vol 7 (10) ◽  
pp. 2639-2642 ◽  
Author(s):  
R.K. Singh ◽  
Deepika Bhattacharya ◽  
S. Sharan ◽  
P. Tiwari ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Rutherford Backscattering Spectrometry ◽  
Pulsed Laser ◽  
High Energy ◽  
Laser Deposition ◽  
Nanosecond Laser ◽  
X Ray ◽  
Target Composition

We have fabricated Ni3Al and NiAl thin films on different substrates by the pulsed laser deposition (PLD) technique. A high energy nanosecond laser beam was directed onto Ni–Al (NiAl, Ni3Al) targets, and the evaporated material was deposited onto substrates placed parallel to the target. The substrate temperature was varied between 300 and 400 °C, and the substrate-target distance was maintained at approximately 5 cm. The films were analyzed using scanning electron microscopy, transmission electron microscopy, x-ray diffraction, and Rutherford backscattering spectrometry. At energy densities slightly above the evaporation threshold, a slight enrichment of Al was observed, while at higher energy densities the film stoichiometry was close (<5%) to the target composition. Barring a few particles, the surface of the films exhibited a smooth morphology. X-ray and TEM results corroborated the formation of Ni3Al and NiAl films from similar target compositions. These films were characterized by small randomly oriented grains with grain size varying between 200 and 400 Å.

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