Showing papers on "Pulsed laser deposition published in 1998"
TL;DR: In this article, a wide gap II-VI semiconductor alloy, MgxZn1−xO, was proposed for the fabrication of heteroepitaxial ultraviolet light emitting devices based on ZnO.
Abstract: We propose a widegap II–VI semiconductor alloy, MgxZn1−xO, for the fabrication of heteroepitaxial ultraviolet light emitting devices based on ZnO. The c-axis oriented MgxZn1−xO films were epitaxially grown by pulsed laser deposition on ZnO epitaxial films and sapphire (0001) substrates using ceramic targets. Solid solution films were prepared with Mg content up to x=0.33, achieving a band gap of 3.99 eV at room temperature. MgO impurity phase segregated at x⩾0.36. Lattice constants of MgxZn1−xO films changed slightly (∼1%), increasing in a axis and decreasing in c-axis direction with increasing x. These films showed ultraviolet photoluminescence at energies from 3.36 (x=0) to 3.87 eV (x=0.33) at 4.2 K.
1,441 citations
TL;DR: In this article, the topmost oxide layer was observed to hydroxylate after immersion in water, which was used to enhance the etch-selectivity of SrO relative to TiO2 in a buffered HF solution.
Abstract: In recent years, well-defined and nearly perfect single crystal surfaces of oxide perovskites have become increasingly important. A single terminated surface is a prerequisite for reproducible thin film growth and fundamental growth studies. In this work, atomic and lateral force microscopy have been used to display different terminations of SrTiO3. We observe hydroxylation of the topmost SrO layer after immersion of SrTiO3 in water, which is used to enhance the etch-selectivity of SrO relative to TiO2 in a buffered HF solution. We reproducibly obtain perfect and single terminated surfaces, irrespective of the initial state of polished surfaces and the pH value of the HF solution. This approach to the problem might be used for a variety of multi-component oxide single crystals. True two-dimensional reflection high-energy electron diffraction intensity oscillations are observed during homo epitaxial growth using pulsed laser deposition on these surfaces.
693 citations
TL;DR: In this paper, the analysis of the X-ray photoelectron spectra (XPS) of the C 1s core level of pulsed laser deposited diamond-like carbon thin films, obtained at different laser intensities is presented.
608 citations
TL;DR: SrCu2O2 thin films were prepared on SiO2 glass substrates by pulsed laser deposition in this article, which showed high optical transmission in visible and near-infrared regions.
Abstract: SrCu2O2 thin films were prepared on SiO2 glass substrates by pulsed laser deposition. The film deposited in O2 atmosphere of 7×10−4 Pa at 573 K showed high optical transmission in visible and near-infrared regions. Potassium was doped at Sr site for substitutional doping. The optical band gap of the K-doped film was estimated to be ∼3.3 eV. The dc electrical conductivity of the K-doped film at 300 K was 4.8×10−2 S cm−1 and the activation energy was 0.10 eV. Positive sign of Seebeck and Hall coefficients demonstrated the p-type conduction of the film. Hole concentration and mobility at 300 K were 6.1×1017 cm−3 and 0.46 cm2 V−1 s−1, respectively.
381 citations
TL;DR: In this article, the dynamics of nanoparticle formation, transport, and deposition by pulsed laser ablation of c-Si into 1-10 Torr He and Ar gases are revealed by imaging laser-induced photoluminescence and Rayleigh-scattered light from gas-suspended 1−10 nm SiOx particles.
Abstract: The dynamics of nanoparticle formation, transport, and deposition by pulsed laser ablation of c-Si into 1–10 Torr He and Ar gases are revealed by imaging laser-induced photoluminescence and Rayleigh-scattered light from gas-suspended 1–10 nm SiOx particles. Two sets of dynamic phenomena are presented for times up to 15 s after KrF-laser ablation. Ablation of Si into heavier Ar results in a uniform, stationary plume of nanoparticles, while Si ablation into lighter He results in a turbulent ring of particles which propagates forward at 10 m/s. Nanoparticles unambiguously formed in the gas phase were collected on transmission electron microscope grids for Z-contrast imaging and electron energy loss spectroscopy analysis. The effects of gas flow on nanoparticle formation, photoluminescence, and collection are described.
318 citations
TL;DR: In this article, the effects of substrate temperature on the properties of ZnO films were investigated and the crystalline, electrical and optical properties of the films were found to depend directly on substrate temperature during deposition.
Abstract: Highly conductive and transparent aluminum- and gallium-doped zinc oxide (ZnO:Al and ZnO:Ga) thin films in place of indium tin oxide films have been prepared by using XeCl excimer laser ablation at relatively low temperatures. The impurity content of Al or Ga in the ZnO target was optimized on the basis of the measurements of resistivity, carrier concentration, and Hall mobility of the deposited transparent conducting ZnO films. The effects of substrate temperature on the properties of ZnO films were investigated. The crystalline, electrical and optical properties of the films were found to depend directly on substrate temperature during deposition. The minimum resistivity of 1.4×10−4 Ω cm was obtained for the ZnO:Al film prepared at a substrate temperature of 300 °C using a ZnO target with an Al2O3 content of 1% by weight (wt %). Moreover, the ZnO:Al film prepared at a substrate temperature of 100 °C showed a low resistivity value of 2.5×10−4 Ω cm. As for the ZnO:Ga film, on the other hand, the minimum r...
247 citations
TL;DR: The main characteristic of the BN-NTs produced by this method is that nanotubes are of only one to three atomic layers thick, which could be attributed to the dominance of the axial growth rate over the radial growth rate as mentioned in this paper.
Abstract: Boron nitride nanotubes (BN-NTs) were synthesized by using excimer laser ablation at 1200 °C in different carrier gases. The main characteristic of the BN-NTs produced by this method is that nanotubes are of only one to three atomic layers thick, which could be attributed to the dominance of the axial growth rate over the radial growth rate. The diameter of the BN-NTs ranged from 1.5 to 8 nm. The tips of the BN-NTs are either a flat cap or of polygonal termination, in contrast to the conical ends of carbon nanotubes. The atomic ratio of boron to nitrogen as measured by means of parallel electron energy loss spectroscopy is 0.8, which is within the experimental error of the stoichiometry of hexagonal BN structure.
218 citations
TL;DR: In this article, the authors investigated the nature of epitaxy, defects (dislocations, stacking faults, and inversion domains), and heterointerfaces in zinc oxide films grown on sapphire and explored the possibility of using it as a buffer layer for growing group III nitrides.
Abstract: We have investigated the nature of epitaxy, defects (dislocations, stacking faults, and inversion domains), and heterointerfaces in zinc oxide films grown on (0001) sapphire and explored the possibility of using it as a buffer layer for growing group III nitrides. High quality epitaxial ZnO films were grown on sapphire using pulsed laser deposition in the temperature range 750–800 °C. The epitaxial relationship of the film with respect to (0001) sapphire was found to be (0001)ZnO∥(0001)sap, with in-plane orientation relationship of [0110]ZnO∥[1210]sap. This in-plane orientation relationship corresponds to a 30° rotation of ZnO basal planes with respect to the sapphire substrate, which is similar to the epitaxial growth characteristics of AlN and GaN on sapphire. The threading dislocations in ZnO were found to have mostly 1/3〈1120〉 Burgers vectors. The planar defects (mostly I1 stacking faults) were found to lie in the basal plane with density of about 105 cm−1. We have grown epitaxial AlN films at tem...
207 citations
TL;DR: In this article, a radiofrequency plasma-enhanced chemical vapor deposition method was used for the deposition of hydrogenated microcrystalline silicon (µc-Si:H) at a relatively high working pressure.
Abstract: The deposition of hydrogenated microcrystalline silicon (µc-Si:H) at a relatively high working pressure is performed using a conventional radio-frequency plasma-enhanced chemical vapor deposition method. Correlation of the deposition rate and crystallinity with deposition parameters, such as working pressure, flow rate, dilution ratio and input RF power, are studied. It was found that the deposition rate exhibits a maximum at around 4 Torr and that the crystallinity of films decreases monotonically with increasing pressure. The combination of SiH4 depletion and high working pressure in the plasma is necessary to improve the crystallinity of films deposited at a high rate. Consequently, a high deposition rate of 9.3 A/s is achieved with high crystallinity and low defect density.
207 citations
TL;DR: In this article, the morphology and microstructure of the Si nanowire tips have been systematically characterized by means of high-resolution transmission electron microscopy, and the results suggest that Si oxide is more important than metal in catalyzing the formation of Si nano-connections.
Abstract: Si nanowires with uniform size have been synthesized by laser ablation of highly pure Si powder targets mixed with SiO2. A bulk quantity of Si nanowires was successfully obtained by mixing 30%–70% of SiO2 into the Si powder target. SiO2 played a crucial role in enhancing the formation and growth of the Si nanowires. The morphology and microstructure of the Si nanowire tips have been systematically characterized by means of high-resolution transmission electron microscopy. No evidence of metal was found at the tips. The results suggest that Si oxide is more important than metal in catalyzing the formation of Si nanowires.
204 citations
TL;DR: In this paper, the top and bottom Fe3O4 layers were grown on MgO substrates with a CoCr2O4 buffer layer to achieve different coercivities.
Abstract: Micron-size magnetic tunnel junctions consisting of ferromagnetic Fe3O4 electrodes, with MgO as a barrier layer, have been fabricated on (100) MgO substrates. Reflection high-energy electron diffraction and transmission electron microscopy studies reveal that the Fe3O4/MgO/Fe3O4 trilayers grown by pulsed laser deposition are heteroepitaxial with abrupt interfaces. To achieve different coercivities for the top and bottom Fe3O4 layers, the trilayers are grown on MgO substrates with a CoCr2O4 buffer layer. The junctions exhibit nonlinear current–voltage characteristics and changes in junction resistance with applied field corresponding to the coercivities of the two magnetic layers. However, the observed magnetoresistance (∼0.5% at 300 K, ∼1.5% at 150 K) is much lower than would be expected for a highly spin-polarized system. Possible reasons for the reduced magnetoresistance are discussed.
TL;DR: Ionized sputter deposition, which uses in-flight ionization of sputtered metal atoms and subsequent film deposition by means of a substrate potential, has been developed as a technique to extend physical vapor deposition into higher aspect ratios as mentioned in this paper.
Abstract: The manufacturing of interconnect features on semiconductor wafers has evolved from lift-off-based evaporation to reactive ion etching metallization and now to Damascene technology Physical sputter deposition has been widely used for blanket metal film deposition, but is impractical for high aspect topographies Filtered, or directional sputter techniques, such as long throw or collimation, have been used for some high aspect ratio applications, but suffer from poor efficiency, high cost, and/or poor scaling Ionized sputter deposition, which uses in-flight ionization of sputtered metal atoms and subsequent film deposition by means of a substrate potential, has been developed as a technique to extend physical vapor deposition into higher aspect ratios
Book•
01 Jan 1998
TL;DR: In this article, the authors present a glossary of terms and acronyms used in surface engineering, including the low-pressure gas and vacuum processing environment and the low pressure plasma processing environment.
Abstract: Introduction * Substrate ("Real") Surfaces and Surface Modification * The Low-Pressure Gas and Vacuum Processing Environment * The Low-Pressure Plasma Processing Environment * Vacuum Evaporation and Vacuum Deposition * Physical Sputtering and Sputter Deposition (Sputtering) * Arc Vapor Deposition * Ion Plating and Ion Beam Assisted Deposition * Atomistic Film Growth and Some Growth-Related Film Properties * Film Characterization and some Basic Film Properties * Adhesion and Deadhesion * Cleaning * External Processing Environment. Appendix 1: Reference Material. Appendix 2: Transfer of Technology for R&D to Manufacturing. Glossary of Terms and Acronyms used in Surface Engineering. Index.
TL;DR: The epitaxial growth of all layers was confirmed by four-circle x-ray diffraction in this paper, where Pb(Mg1/3Nb2/3)-PbTiO3 (PMN-PT) (70/30) films were deposited by pulsed laser deposition from Pb-enriched ceramic targets.
Abstract: (001)-oriented heterostructures consisting of LaAlO3 substrates, SrRuO3 bottom electrodes, and Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN-PT) (70/30) films were deposited by pulsed laser deposition from Pb-enriched ceramic targets. The epitaxial growth of all layers was confirmed by four-circle x-ray diffraction. Film growth was carried out over a wide range of processing space where substrate temperature, ambient pressure, and laser parameters were varied in order to determine suitable conditions for producing high quality crystals with good electrical properties. In general, strong similarities were observed between thin film and ceramic processing of the same compositions. The associated pyrochlore phase was very difficult to avoid and, in the absence of excess Pb-containing second phases, could only be done at very high temperatures and high oxygen/ozone pressures for films on LaAlO3 substrates. When deposited at temperatures below approximately 640 °C, PMN-PT films grown from lead-enriched targets exhibited depres...
TL;DR: The microstructures of these Y2O3 films were found to be highly dependent on the deposition temperature and the amount of O2 gas used during the deposition process as mentioned in this paper.
Abstract: Yttrium oxide, Y2O3, films were prepared by pulsed laser deposition in the presence of oxygen (O2) gas. The microstructures of these films were found to be highly dependent on the deposition temperature and the amount of O2 gas used during the deposition process. X-ray diffraction (XRD) analysis showed that the Y2O3 films transformed from amorphous to polycrystalline form when the deposition temperature was increased to 350 °C at an O2 pressure of 0.01 mbar, and an extremely strong XRD peak originated from Y2O3(111) orientation was observed when the deposition temperature was increased above 400 °C. However, during the deposition at a fixed temperature (650 °C), the Y2O3 films became amorphous when the O2 pressure was successively increased. For the films deposited on either fused silica or silicon substrate between 150 and 650 °C, very smooth surface morphologies with an average surface roughness of 0.4–19 nm have been observed by an atomic force microscopy. UV/Visible spectrometer and Fourier transform ...
Patent•
28 May 1998TL;DR: In this article, a film of a coating material is produced on a substrate (22) by a pulsed laser deposition method in which the material that forms the coating material was first combined with a matrix material to form a target (16), and the target was then exposed to a source of laser energy (12) to desorb the matrix material from the target and lift the surface of the target.
Abstract: A film of a coating material is produced on a substrate (22) by a pulsed laser deposition method in which the material that forms the coating material is first combined with a matrix material to form a target (16). The target (16) is then exposed to a source of laser energy (12) to desorb the matrix material from the target (16) and lift the coating material from the surface of the target (16). The target (16) and the substrate (22) are oriented with respect to each other so that the lifted coating material is deposited as a film upon said substrate (22). The matrix material is selected to have the property of being more volatile than the coating material and less likely than the coating material to adhere to the substrate (22). The matrix material is further selected as having the property such that when the target (16) is exposed to a source of laser energy (12), the matrix material desorbs from the target (16) and lifts the coating material from the surface of the target (16). In another aspect of the invention, a method of making an improved chemical or biochemical sensing device that includes a chemoselective or bioselective coating on a substrate (22) is carried out by coating the substrate (22) by pulsed laser deposition.
TL;DR: The transport and magnetic properties of magnetite (Fe3O4) thin films grown epitaxially on single crystal MgO(100) and SrTiO3 (100) substrates, and with multiple grain orientations on polycrystalline Sr TiO3 substrates have been investigated in this paper.
Abstract: The transport and magnetic properties of magnetite (Fe3O4) thin films grown epitaxially on single crystal MgO(100) and SrTiO3(100) substrates, and with multiple grain orientations on polycrystalline SrTiO3 substrates, have been investigated. The films are grown using pulsed laser deposition and their epitaxial quality determined using ion channeling measurements. Transport and magnetic studies of Fe3O4 films as a function of thickness and morphology suggest that epitaxial strain and growth defects affect the width and temperature of the Verwey transition. In addition, these factors also significantly influence the magnetic coercivity of the films. The low-field magnetoresistance (MR) behaviors of epitaxial and polycrystalline films as a function of temperature have been compared and they were found to be quite similar, suggesting very small contribution to the MR from grain boundaries.
TL;DR: In this article, the photoluminescence (PL) and cathodoluminecence (CL) brightness data obtained from Europium-doped yttrium oxide (Eu:Y2O3) luminescent thin films have been grown in situ on single crystal (0001) sapphire substrates using a pulsed laser deposition technique.
Abstract: Europium-doped yttrium oxide (Eu:Y2O3) luminescent thin films have been grown in situ on single crystal (0001) sapphire substrates using a pulsed laser deposition technique. The films grown under different deposition conditions have been characterized using microstructural and luminescent measurements. The photoluminescence (PL) and cathodoluminescence (CL) brightness data obtained from the Eu:Y2O3 films grown under optimized conditions have indicated that sapphire is a promising substrate for the growth of high quality Eu:Y2O3 thin film red phosphor. The success in the fabrication of Eu:Y2O3 films with high PL and CL brightness is attributed to favorable optical properties (low absorption of and low refractive index for red light) of the substrate material and improved growth of grains with unidirectional orientation on (0001) sapphire substrates.
TL;DR: The surface of the resulting films was confirmed to be extremely flat, showing atomically smooth terraces and 0.4 nm high steps corresponding to a unit cell height of perovskite as mentioned in this paper.
Abstract: La0.6Sr0.4MnO3 thin films were fabricated on SrTiO3 (001) substrates using pulsed laser deposition with observing persistent intensity oscillation of reflection high-energy electron diffraction. By atomic force microscopy, the surface of resulting films was confirmed to be extremely flat, showing atomically smooth terraces and 0.4 nm high steps corresponding to a unit cell height of perovskite. The surface terminating atomic layer was unambiguously assigned to the MnO2 layer by coaxial impact collision ion scattering spectroscopy. Crystal symmetry of the films is distorted into a tetragonal one due to the strain to fulfill perfect in-plane matching with the substrate even for films as thick as 100 nm. Even for films as thin as 4 nm (10 unit cells), ferromagnetic transition takes place to induce a metallic state and large negative magnetoresistance is observed as well.
TL;DR: In this article, the authors present low-frequency dielectric loss and nonlinearity measurements in SrTiO3 thin films grown by pulsed laser deposition on SrRuO3 electrode layers.
Abstract: We present low-frequency dielectric loss and nonlinearity measurements in SrTiO3 thin films grown by pulsed laser deposition on SrRuO3 electrode layers. A low loss tangent in the order of 10−4, close to the level found in SrTiO3 single crystals, was observed. Combined with a large tunability, this resulted in a figure of merit for frequency and phase agile materials that can rival that observed in single crystals. The result is potentially significant for tunable microwave device applications, and it points to stress and interface effects as the possible causes for higher dielectric losses in thin films.
TL;DR: In this paper, a comparison of the different characteristic features associated with the AlN films deposited by pulsed laser deposition or magnetron sputtering is presented with particular emphasis to electronic and tribological applications.
Abstract: Aluminum nitride films have been deposited on Si(111) substrates at different substrate temperatures using two techniques; pulsed laser deposition or reactive magnetron sputtering. The films deposited by either of the techniques have been characterized by x-ray diffraction and transmission electron microscopy to determine the crystalline quality, grain size, and epitaxial growth relation with respect to the substrate. The bonding characteristics and the residual stresses present in the films have been evaluated using Raman and Fourier transform infrared spectroscopy. Secondary ion mass spectrometry has been performed to determine the nitrogen stoichiometry and the presence of impurities such as oxygen and silicon. The adhesion strength of the AlN films to the silicon substrate and the wear resistance have been determined by scratch test and a specially designed microscopic wear test. A comparison of the different characteristic features associated with the AlN films deposited by pulsed laser deposition or magnetron sputtering is presented with particular emphasis to electronic and tribological applications.
TL;DR: In this article, BaTiO3/SrTiOO3 multilayered thin films were deposited on Si and Pt/Si substrates and X-ray diffraction clearly showed the formation of the superstructures.
Abstract: BaTiO3/SrTiO3 multilayered thin films were deposited on Si and Pt/Si substrates. X-ray diffraction clearly shows the formation of the superstructures. Phase transition properties were studied via dielectric measurements. Glassy behavior, characterized by a strong frequency dispersion of dielectric properties, was found in samples with a total thickness of 400 nm, while in samples with a total thickness of 800 nm, normal ferroelectric phase transitions with two dielectric peaks were observed. A preliminary interpretation assumes that size effects which frustrate long range ferroelectric ordering may lead to the relaxational behavior in BaTiO3/SrTiO3 superstructures.
TL;DR: In this paper, the structural properties of c-axis oriented BaTiO3 thin films on MgO(001) have been characterized by Rutherford backscattering spectrometry/ion channeling (RBS/C), x-ray diffraction, and atomic force microscopy.
Abstract: Epitaxial waveguide structures of c-axis oriented BaTiO3 thin films on MgO(001) have been grown by pulsed laser deposition. The structural properties of the samples have been characterized by Rutherford backscattering spectrometry/ion channeling (RBS/C), x-ray diffraction, and atomic force microscopy. We found excellent crystalline quality even up to thicknesses of a few microns. This has been confirmed by RBS/C minimum yield values of 2%–3%, a full width at half maximum of 0.36° of the BaTiO3 (002) rocking curve, and a rms roughness of 1.1 nm for a 950 nm BaTiO3 film. The out-of-plane refractive index was measured to be close to the extraordinary bulk value with the birefringence being about one third of the bulk value. Waveguide losses of 2.9 dB/cm have been demonstrated.
TL;DR: Using pulsed laser deposition (PLD), metastable perovskite YMnO3 films were grown from a hexagonal target and X-ray and electron diffraction confirm the films' epitaxial nature but evince that the orientation and residual strains depend on the substrate as discussed by the authors.
Abstract: Using pulsed laser deposition (PLD), metastable perovskite YMnO3 films were grown from a hexagonal YMnO3 target. The stabilization of the metastable phase is a result of the structural similarity between it and the perovskite substrates. X-ray and electron diffraction confirm the films' epitaxial nature but evince that the orientation and residual strains depend on the substrate. The implication of these findings is that PLD is a simple synthetic approach to stabilizing new, more complex, metastable perovskites.
TL;DR: The shape of the cyclic voltamogram is very sensitive to the composition and morphology of the spinel and the diffusion process for thin films of LiMn{sub x}Mn {sub 2}O{sub 4} spinel prepared by pulsed laser deposition were studied using constant current cycling as mentioned in this paper.
Abstract: Electrochemical properties of thin films of Li{sub x}Mn{sub 2}O{sub 4} spinel prepared by pulsed laser deposition were studied using constant current cycling and cyclic voltammetry Films have been cycled more than 220 times with no significant capacity fading The shape of the cyclic voltammogram is very sensitive to the composition and morphology of the film, The diffusion process for the Li{sub x}Mn{sub 2}O{sub 4} thin films with an excess of lithium (x > 1) appears to be slower than for lithium-deficient films Films were subjected to overcharge (5 V vs Li/Li{sup +}) and overdischarge (2 V vs Li/Li{sup +}) Overcharge does not significantly affect the structure of the film Overdischarge leads to changes in the shape of the cyclic voltammogram: (1) loss of resolution of the two oxidation peaks at 41 and 42 V which are the signatures of the spinel structure, and (2) loss of capacity These changes in the electrochemical behavior may be correlated to the structural disorder associated with the phase transition when more than one lithium is intercalated in LiMn{sub 2}O{sub 4} It is a reversible phenomenon
TL;DR: In this paper, a thin-film lead-zirconate-titanate (PZT) capacitors with composition gradients normal to the substrate were fabricated using pulsed laser deposition.
Abstract: Thin-film lead–zirconate–titanate (PZT) capacitors with composition gradients normal to the substrate were fabricated via a novel technique using pulsed laser deposition. These capacitors exhibited large polarization offsets when driven by an alternating electric field. The direction of the offsets depended on the direction of the gradient with respect to the substrate. The largest offset, greater than 400 μC/cm2 when driven with a 50 V/μm field, was nearly an order of magnitude greater than any reported for other graded ferroelectric films. This difference is attributed to both the high spontaneous polarization of PZT and the high-quality films obtained by pulsed laser deposition.
TL;DR: In this article, a self-assembling bismuth-containing nano-electroded cells of layered perovskite ferroelectric thin films that are about 200 nm in size were grown by pulsed laser deposition (PLD) on top of epitaxial conductive La 0.5Sr0.5CoO3 (LSCO) layers equally deposited by PLD.
Abstract: In the present work, we report self-assembling bismuth-containing nano-electroded cells of layered perovskite ferroelectric thin films that are about 200 nm in size, that is 50 times smaller than the smallest cell reported to date. Heteroepitaxial Bi-rich Bi4Ti3O12 films were grown by pulsed laser deposition (PLD) on top of epitaxial conductive La0.5Sr0.5CoO3 (LSCO) layers equally deposited by PLD. The epitaxial LSCO has been grown on top of an epitaxial CeO2 yttrium-stabilized zirconia (YSZ) stack, itself deposited by PLD on Si(100) substrates. As a consequence of the high substrate temperature during the epitaxial deposition of the Bi4Ti3O12 layer, the excess Bi segregates, migrates to the surface where it forms a self-organized array of epitaxial mesas which possess metallic-like electrical characteristics.
TL;DR: In this paper, the authors used pulsed arc currents and laser controlled ignition (Laser-Arc) to overcome the usual problems in arc ablation of carbon targets, and very hard amorphous carbon films with hardness in the superhard range between 40 and 80 GPa were prepared with high deposition rates comparable to conventional industrial arc deposition.
Abstract: The deposition of superhard amorphous carbon films demands high energies of all impinging particles for film formation by subplantation instead of condensation. Such conditions may be realized by vacuum arc discharge. By using pulsed arc currents and laser controlled ignition (Laser-Arc) the usual problems in arc ablation of carbon targets have been overcome. In this way, smooth and very hard films with hardness in the superhard range between 40 and 80 GPa have been prepared with high deposition rates comparable to conventional industrial arc deposition. Due to the high ion energies, low deposition temperatures are possible without reducing the adherence. They are even necessary for the formation of the diamond bonds by avoiding relaxation towards a graphitic structure. Hence, materials besides metals such as steels or aluminum, temperature-sensitive materials such as polymers have been successfully coated with these hard layers.
TL;DR: In this paper, thin films of crystalline polytetrafluoroethylene (PTFE) were prepared by pulsed-laser deposition using 248 nm UV-excimerlaser radiation.