ICMCTF2000 Session HP: H Poster
Tuesday, April 11, 2000 5:00 PM in Room Atlas Foyer
Tuesday Afternoon
Time Period TuP Sessions | Topic H Sessions | Time Periods | Topics | ICMCTF2000 Schedule
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HP-1 XPS and FT-IR Study of Changes in Chemical States of PET due to Low Energy Oxygen Ion Beam
K. Yamaguchi, A.M. Ektessabi (Kyoto University, Japan) The effects of low energy ion irradiation on the morphological, structural, and chemical states of the surface of a polymer are studied. PET (polyethylene terephthalate) thin film (thickness: 28µm), which has a wide range of applicable potential as a material for medical implant and electrical industry, was irradiated with low energy oxygen ions of variable doses. The treated films were investigated by three kinds of techniques. AFM (Atomic Force Microscopy) revealed that an increase in dose caused an increase in surface roughness. The changes in chemical structure and surface chemical composition were confirmed by FT-IR (Fourier Transform Infrared) and XPS (X-ray Photoelectron Spectroscopy) respectively. The simulation by means of SRIM code was also performed to clarify the distribution of oxygen ions in PET film after irradiation. The scission of PET film's chemical components in the surface was induced by low energy oxygen ion irradiation and it caused a decrease in O1s/C1s atomic mass ratio. |
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HP-2 Evaluation of Ferroelectric Properties of Perovskite Oxides with LaNiO3 as Electrodes
V. Mangasuli (University of Alabama); R. Katare, M.D. Yeasin, A. Kumar (University of South Alabama) The use of perovskite type conductive materials as electrodes favors the growth of high quality ferroelectric thin films. Here we have successfully grown epitaxial conductive LaNiO3 (LNO) thin films on Si(100) and LaAlO3 substrates using pulsed laser deposition technique. On this electrode we have grown high quality thin films of ferroelectric materials like barium strontium titanate(BST). The investigation of the multilayer by scanning electron microscopy and X-ray diffraction respectively reveal the smooth morphology and the orientedness of the LNO, and BST layers. The ferroelectric properties of the multilayer cells are then tested using the HP 9412A impedance analyzer, Keithley 617 electrometer and RT66A Standardized Ferroelectric test system.} |
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HP-3 The Electrical and Ferroelectric Properties of Perovskite Oxides
V. Mangasuli (University of Alabama); M.D. Yeasin, R. Katare, A. Kumar (University of South Alabama) Thin epitaxial grown films of the perovskite BaTiO3, PbTiO3 and SrTiO23 are of interest in the construction of devices such as thin film capacitors and pyroelectric detectors. In this study we have grown high quality BaTiO3, PbTiO3 and SrTiO3 films on Si(100) by the pulsed laser ablation technique under the optimized conditions. The structure and the morphology of the films are characterised by X-ray diffraction technique and scanning electron microscopy respectively. The electrical characterisation of the films is done by the low temperature resistivity technique. The films are then tested for their feroelectric behaviour by HP 9412A impedance analyzer and RT66A Standardized Ferroelectric test system.} |
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HP-4 TiC and TiC/C Film Formation by Reactive Sputter Ion Plating
M. Sonobe, M. Yasuoka (Nach-Fujikoshi Corp., Japan) TiC film of PVD is deposited first by ion-plating but is unstable to form in fact. Reactive sputter ion-plating is easy to controll various parameters of the process. TiC/C film was formed by rich reactive gas and was shown as low friction coefficents closed to DLC by a pin on disk friction tester. The result sugested that TiC/C film is able to apply cutting tools and resistance wear parts for practical use. And the method is indicated a hybrid system of PVD + PCVD. |
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HP-5 Transparent Conducting Zinc Oxide Thin Films Grown by Pulsed Laser Deposition for Organic Light-emitting Devices
H. Kim, A. Piqué, J.S. Horwitz, H. Murata, Z.H. Kafafi, D.B. Chrisey (US Naval Research Laboratory) Transparent conducting aluminum- and gallium-doped zinc oxide (ZnO:Al and ZnO:Ga) thin films were deposited on glass substrates by pulsed laser deposition. Target composition with impurity content of Al (0 - 4 wt%) or Ga (0 – 4 wt%) was optimized to achieve the minimum film resistivity. The effect of substrate deposition temperature and oxygen background pressure on the structural, electrical and optical properties of these films were investigated. Films were deposited using a KrF (248nm, 30 ns FWHM) excimer laser at fluence from 1 to 2 J/cm2. Films were deposited at substrate temperatures ranging from room temperature to 400 oC in oxygen pressures ranging from 1 to 100 mTorr. The structure, morphology, optical and electrical properties of the deposited films were measured using X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM), UV-IR absorption spectrometry, and Hall effect measurements, respectively. For the ZnO:Al film (~ 300 nm) deposited at 200 ?C using a ZnO target with an Al content of 0.8 wt%, the electrical resistivity was 3.7 x 10 -4 ?-cm and the average transmission in the visible range (400 – 700 nm) was 90 %. For the ZnO:Ga films (~ 300 nm) grown at 200 ?C from a ZnO target with a Ga content of 2 wt%, the electrical resistivity was 4.5 x 10 -4 ?-cm and the average transmission in the visible range was 91 %. The properties of both ZnO:Al and ZnO:Ga films will be compared to those of commercially available ITO films and the use of these films as transparent electrodes for organic light emitting devices will be discussed. |
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HP-6 Growth of Doped SrS Thin Films by Pulsed Laser Deposition
A. Piqué, R.Y. Auyeuns, S.B. Qadri, B. Justus, A. Huston (US Naval Research Laboratory) High quality luminescent thin films of doped strontium sulfide (SrS) have been grown using Pulsed Laser Deposition (PLD). SrS films double doped with Eu and Sm, Ce and Sm as well as Cu and Gd were deposited with thicknesses ranging from 0.05 to 2 µm over MgO (001) and glass substrates. Deposition parameters such as growth temperature and H2S background gas pressure were varied and their effect on the structure, morphology and luminescence of the films was evaluated. The PLD grown films all showed texture and were highly oriented when deposited on MgO substrates as determined by their XRD spectra. Optical microscopy, SEM and AFM analysis were used to study the films’ surface morphology. The thermally and optically stimulated luminescence properties of these films were evaluated as well. The properties of these films has been compared to those of bulk doped SrS. The data indicates that these films would be well suited for display applications. |
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HP-7 Coherent Structure Bonds of Composite Materials Layers
V. Vostrikov, I. Plotnikov, M. Lapshov, J. Plotnikova, A. Briylkin, P. Vostrikov (BIMETALL GmbH & Co., Russia) In this paper, composite layered materials based on solid Fe solutions are investigated. The parameters of high temperature thermomechanical treatment are determined for strong coherent interfaces as well as the formation of optimal structure and crystallographie texture in diffusion zone. It is also ascertained that solid Fe solutions have the property to form stable phases with modulated structures in diffusion zone within the interval of temperatures of spinodale trasformation under given gradient of elastic microdistortions in crystal lattice. The thermodynamic model of dissociation of solid solutions in the field of thermoelastic tentions is developed. The eguations for the free energy (F) of elastically deformed crystal structure are derived: F(0) -F(epsolyn)= -1/2E(t)epsolyn2 - 3Eo-αo-Tepsolyn; where epsolyn>0 - with solid expansion; epsolyn,0 - with solid F(0) -F(α) = -α2/(2epsolyn- 3αsub otsub ocompression;epsolyn = (aepsolyn - ao)/asubm o; δ=Eepsolyn. From these expressions it follows that increase in the elastic energy of crystal structures stimulates dissociation of solid solutions, and change in the entropy leads to relaxation of the structures’ elastic energy due to a more homogeneons distribution of the crystal lattice’s microdistortions over the whole volume of the material by way of forming a dispersed modulated structure. The processes of formation of modulated structures with coherent interfaces between bimetal layers in diffusion zone allow to develop new composite materials with a wide spectrum of applications. |