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Book Pulsed Laser Deposition of Bi sub 2 sub Te sub 3 sub Based Thermoelectric Thin Films

Download or read book Pulsed Laser Deposition of Bi sub 2 sub Te sub 3 sub Based Thermoelectric Thin Films written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film thermoelectric coolers offer several advantages that include reliability and integration with device processing. Successful thin film thermoelectric cooling requires integration with thin film diamond or aluminum nitride heat spreaders and the device wafers. Numerous deposition techniques have been attempted previously including evaporation, flash evaporation, molecular beam epitaxy, chemical vapor deposition, and sputtering. In the case of thermoelectric thin films, a primary difficulty is maintaining stoichiometry. In the present effort, thin films of p-type Bi[subscript 0.5]Sb[subscript 1.5]Te3, n-type Bi2Te[subscript 2.7]Se[subscript 0.3] and n-type (Bi2]Te3)90(Sb2Te3)5(Sb2Se3)5 (with 0.13 wt.% SbI3) were deposited on mica and aluminum nitride substrates using Nd-YAG pulsed laser deposition. The film quality in terms of composition and crystal perfection was studied as a function of growth temperature. The films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) for crystalline quality, and by scanning electron microscopy (SEM) for surface morphology. The films showed uniform thickness and high crystalline quality with a preferred (0 0 n) alignment with the substrates. The Seebeck coefficient, electrical resistivity and Hall mobility were measured and compared with the bulk properties. An improvement in the thermoelectric properties by reduction in laser induced particulates has been demonstrated by the use of lower incident laser energy. The thermoelectric characteristics of the films deposited on AlND Si substrates were found to be superior to those deposited on mica substrates. X-ray mapping and energy-dispersive-spectroscopy were performed to determine the composition and homogeneity of the thin films. The results showed that pulsed laser deposition has the ability to produce congruent transfer of the target composition to the thin.

Book Pulsed Laser Deposition of Epitaxial Sr RuxSn sub 1 x O3 Thin Film Electrodes and KNbO3 Sr RuxSn sub 1 x O3 Bilayers

Download or read book Pulsed Laser Deposition of Epitaxial Sr RuxSn sub 1 x O3 Thin Film Electrodes and KNbO3 Sr RuxSn sub 1 x O3 Bilayers written by and published by . This book was released on 1995 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sr(RuxSn{sub 1-x})3 is proposed as a new conducting oxide for use in epitaxial multilayer structures. The Sr(Ru{sub o} 4Sn{sub 0.52})03 composition exhibits an excellent lattice match with (100)-oriented KTaO3, and films of this composition grown by pulsed laser deposition on KTaO3, SrTiO3, and LaAlO3 substrates have been analyzed by X-ray diffraction, Rutherford backscattering/ion channeling, and resistivity measurements. Epitaxial KNbO3/Sr(Ru{sub 0.48}Sn{sub 0.52})O3 bilayers have been successfully grown.

Book Current Research in Pulsed Laser Deposition

Download or read book Current Research in Pulsed Laser Deposition written by Liviu Duta and published by MDPI. This book was released on 2021-08-30 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite its limitation in terms of surface covered area, the PLD technique still gathers interest among researchers by offering endless possibilities for tuning thin film composition and enhancing their properties of interest due to: (i) the easiness of a stoichiometric transfer even for very complex target materials, (ii) high adherence of the deposited structures to the substrate, (iii) controlled degree of phase, crystallinity, and thickness of deposited coatings, (iv) versatility of the experimental set-up which allows for simultaneous ablation of multiple targets resulting in combinatorial maps or consecutive ablation of multiple targets producing multi-layered structures, and (v) adjustment of the number of laser pulses, resulting in either a spread of nanoparticles, islands of materials or a complete covering of a surface. Moreover, a variation of PLD, known as Matrix Assisted Pulsed Laser Evaporation, allows for deposition of organic materials, ranging from polymers to proteins and even living cells, otherwise difficult to transfer unaltered in the form of thin films by other techniques. Furthermore, the use of laser light as transfer agent ensures purity of films and pulse-to-pulse deposition allows for an unprecedented control of film thickness at the nm level. This Special Issue is a collection of state-of-the art research papers and reviews in which the topics of interest are devoted to thin film synthesis by PLD and MAPLE, for numerous research and industry field applications, such as bio-active coatings for medical implants and hard, protective coatings for cutting and drilling tools withstanding high friction and elevated temperatures, sensors, solar cells, lithography, magnetic devices, energy-storage and conversion devices, controlled drug delivery and in situ microstructuring for boosting of surface properties.

Book Pulsed Excimer Laser Deposition of Ferroelectric Thin Films

Download or read book Pulsed Excimer Laser Deposition of Ferroelectric Thin Films written by S. B. Krupanidhi and published by . This book was released on 1991 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsed UV excimer laser ablation was employed to deposit multi-axial, bi-axial and uni-axial ferroelectric compositions of PZT, bismuth titanate and lead germanate respectively. In general, a fluence lower than 2 J/cm2 caused a preferential evaporation of volatile components, resulting in stoichiometric imbalance. However, the fluences beyond 2 J/cm2 enabled the deposition of stoichiometric thin films of multi-component oxide systems. The intrinsic bombardment due to the energetic ablated species during the thin film deposition seemed to influence the composition, structure, orientation and the electrical properties. The electrical characterization of ferroelectric films indicated a dielectric constant of 800-1000, a P, of 32 micron C/cm2 and E sub c of 130KV/cm for polycrystalline PZT films and the corresponding quantities were measured to be 150, 7 micron C/cm2 and 20 KV/cm for in-situ crystallized c-axis preferred oriented bismuth titanate films. Lead germanate thin films oriented along c-axis (OO3) showed a dielectric constant of 30, a P sub r of 2.5 micron C/cm2 and E sub c of 55 KV/cm.

Book Epitaxial Pb Zr sub X Ti sub 1 minus x O sub 3 SrRuO sub 3 x

Download or read book Epitaxial Pb Zr sub X Ti sub 1 minus x O sub 3 SrRuO sub 3 x written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Epitaxial SrRuO[sub 3] thin films were deposited on SrTiO[sub 3](100) and MgO(100) substrates by RF sputtering for use as bottom electrodes and epitaxial buffer layers. On these conductive substrates, epitaxial Pb(Zr[sub x]Ti[sub 1[minus]x])O[sub 3] (PZT; x= 0.35,0.65) and PbTiO[sub 3] (PT; x= 0) thin films were deposited by metalorganic chemical vapor deposition (MOCVD). X-ray diffraction (XRD), RBS channeling (RBS), transmission electron microscopy (TEM) and optical waveguiding were used to characterize the phase, microstructure, defect structure, refractive index, and film thickness of the deposited films. The PZT and PT films were epitaxial and c-axis oriented. 90[degree] domains, interfacial misfit dislocations and threading dislocations were the primary structural defects, and the films showed as high as a 70% RBS channeling reduction. Ferroelectric hysteresis and dielectric measurements of epitaxial PZT ferroelectric capacitor structures formed using evaporated Ag top electrode showed: a remanent polarization of 46.2[mu]C/cm[sup 2], a coercive field of 54.9 kV/cm, a dielectric constant of 410, a bipolar resistivity of[approximately]5.8[times] 10[sup 9][Omega]-cm at a field of 275 kV/cm, and a breakdown strength of>400 kV/cm. Cyclic fatigue measurements showed that the remanent polarization was maintained for>10[sup 9] cycles.

Book Laser Ablation Synthesis and Properties of Epitaxial YBa Sub 2 Cu Sub 3 O Sub 7 Delta

Download or read book Laser Ablation Synthesis and Properties of Epitaxial YBa Sub 2 Cu Sub 3 O Sub 7 Delta written by and published by . This book was released on 1991 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsed laser ablation has been used to fabricate epitaxial superlattices in which c-axis-perpendicular YBa2Cu3O{sub 7-{delta}} (YBCO) layers as thin as a single unit cell are separated by semiconducting PrBa2Cu3O{sub 7-{delta}} (PBCO) layers. The superlattice {Tc} (R=0) decreases rapidly with increasing PBCO thickness, but then saturates at {Tc}(approximately)19 K, 54 K, 71 K, or 80 K, for structures containing isolated, 1-,2-,3-, or 4-cell-thick YBCO layers, respectively. Recent theoretical analyses suggest that the decrease of {Tc} and broadening of the resistive transition for the thinnest YBCO layers is most likely due either to a crossover from 3D to 2D resistive behavior, or to hole-filling in the YBCO layers caused by electron transfer from the PBCO. We find that the resistance in the superconducting transition region scales with temperature as expected for dissipation by characteristically 2D (vortex) excitations. Departures from the universal'' resistance behavior expected for a 2D Ginzburg-Landau Coulomb gas, as the YBCO thickness is increased or the PBCO thickness is decreased, can be attributed to the onset of phase coupling between the YBCO layers. Thus, the experiments show that YBCO's effective anisotropy can be greatly increased by separating very thin YBCO layers by thicker PBCO layers in superlattice structures. As a results, characteristic 2D dissipation can be observed over a greatly expanded temperature range, relative to both thicker-film and single-crystal YBCO specimens. Experiments also were carried out using two additional isostructural sets of superlattices in which the PBCO layers were replaced by more conductive Y- or Ca-doped PBCO layers, in order to alter any electron transfer from PBCO to YBCO.

Book Preparation of PbTiO Sub 3 Thin Films by Laser Ablation

Download or read book Preparation of PbTiO Sub 3 Thin Films by Laser Ablation written by Masanori Okuyama and published by . This book was released on 1991 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: PbTiO3 thin films have been deposited on Si or Pt substrates by laser ablation method using ArF excimer or YAG laser. Species evaporated in the vacuum have been studied by mass analysis, and the measured Pb and Ti are not oxidized. Spacial distributions of the deposition rates on the substrate have been studied as a parameter of laser fluence. The excimer laser gives better films than the YAG. Perovskite films have been obtained at substrate temperature approximately 400 deg C and appropriate ambient O2 gas pressure.

Book Pulsed Laser Deposition Of Thin Films

Download or read book Pulsed Laser Deposition Of Thin Films written by D.B. Chrisey and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Epitaxial Ge Sb Te Thin Films by Pulsed Laser Deposition

Download or read book Epitaxial Ge Sb Te Thin Films by Pulsed Laser Deposition written by Erik Thelander and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Pulsed Laser Deposition of AlMgB14 Thin Films

Download or read book Pulsed Laser Deposition of AlMgB14 Thin Films written by Jason Curtis Britson and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Sub picosecond Laser Deposition of Thin Films

Download or read book Sub picosecond Laser Deposition of Thin Films written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The 1999 Nobel Prize in Chemistry recognized the importance and growing maturity of the femtosecond time-scale in science and engineering. Understanding the interaction between materials and high energy density light to manufacture and process materials has become a key issue in both programmatic and fundamental research at Lawrence Livermore National Laboratory. We have emphasized in this research the aspects related to producing thin films by ablation of material with intense ultra-short laser pulses. Our effort during FY2000 has been focused on building the foundation of this research using high purity graphite as the initial ablation material. We have deposited diamond-like carbon (DLC) in vacuum, measured ablation rates, and characterized the physical and chemical properties of the films. We successfully completed our first objective to compare the microstructure and materials properties of the films deposited using lasers operated in the femtosecond and nanosecond pulse length regime. The mechanical characterization of the deposits showed improved film-substrate adhesion properties that allowed us to build 200-[mu]m thick layers using 150 fs pulses. Films produced with ns-pulses delaminated as soon as the thickness reached only a couple of microns. The stresses in the films were greatly influenced by the fluence and the duration of the laser pulses. The microstructure and surface morphology of the films did not vary significantly with the processing parameters studied (pulse length and fluence). Finally, we demonstrated that it is possible to significantly increase the deposition rate with shorter pulses at a given fluence. In particular, carbon could be deposited at a rate of 25 [mu]m/hour with this technology. Our goal in FY2001 is to study and model the relationship between the ablation plume characteristics (energy, charge, mass, and momentum) and the film growth behavior in order to influence and optimize the deposition process. We also want to determine if the laser parameters influence the stoichiometry of the deposits when compounds or alloys are used as ablation targets. We plan to investigate materials such as TiC, SiC, AlN, and polymers for the study.

Book Deposition of Polypyrrole Thin Films by Advanced Method

Download or read book Deposition of Polypyrrole Thin Films by Advanced Method written by Dušan Kopecký and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of new types of electronic devices based on conductive polymers requires precise and controlled deposition of these materials in thin layers. This book examines the latest results in research of deposition of polypyrrole (PPY) thin films by advanced method - Matrix Assisted Pulsed Laser Evaporation (MAPLE). It also provides a brief survey of the laser deposition of conductive polymers, theoretical analysis of the mechanisms of deposition by MAPLE method, definition of both source-PPY properties and deposition conditions necessary for successful thin layer fabrication.