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Presents a study which examined highly carbon-doped gallium arsenide epilayers grown by low-pressure metalorganic vapor phase epitaxy using high-resolution x-ray diffraction. Information on carbon-doping; Methodology; Results.

Presents a study that investigated gallium compound interfaces grown by low-pressure metalorganic vapor phase epitaxy at various temperatures and in different structures. Use of photoluminescence method; Results of the examination on gallium compound using x-ray diffraction measurements and simulations with dynamical theory.

Quasi-free-standing epitaxialgraphenegrown on wide band gap semiconductorSiC demonstrates high carrier mobility and good material uniformity, which make it promising for graphene-based electronic devices. In this work, quasi-free-standing bilayer epitaxialgraphene is prepared and its transistors with gate lengths of 100 nm and 200 nm are fabricated and characterized. The 100 nm gate length graphenetransistor shows improved DC and RF performances including a maximum current density Ids of 4.2 A/mm, and a peak transconductance gm of 2880 mS/mm. Intrinsic current-gain cutoff frequency fT of 407 GHz is obtained. The exciting DC and RF performances obtained in the quasi-free-standing bilayer epitaxialgraphenetransistor show the great application potential of this material system. [ABSTRACT FROM AUTHOR]

Abstract: PbZr1−x Ti x O3 (PZT) has been intensively studied for various ferroelectric applications. Its promising application for micro-electro-mechanical system has reignited the interests due to its outstanding ferroelectric and piezoelectric properties. Most PZT ceramics employed in devices are synthesized with a Zr/Ti ratio close to the tetragonal–rhombohedral morphotropic phase boundary (x =0.48) due to its high electro-mechanical coupling at this composition. Morphotropic phase boundary is particularly interesting to study for the investigation of phase transition. In this work, we report the epitaxial growth and electrical characterization of epitaxial PZT (Zr/Ti=52/48) thin films on Nb-doped SrTiO3. PZT films, with thickness from 30nm to 65nm, were deposited by sol–gel method and eventually crystallized at 700°C by rapid thermal annealing in oxygen. Film ferroelectricity was confirmed by Sawyer–Tower circuit measurement. X-ray diffraction analysis indicates a thickness-dependent structural phase, i.e., a phase transition from tetragonal phase for the thinner film to a biphasic (tetragonal+pseudo-cubic) structure for the thicker film, which is characterized by ellipsometry as a phase separation from the bottom surface of the film to the top one. This phase transition is related to a composition gradient within the film thickness. [Copyright &y& Elsevier]

By using highly conductive p-type La0.7Sr0.3MnO3 (LSMO) and n-type La0.07Sr0.93SnO3 (LSSO) as electrodes, all-oxide Pb(Zr0.52Ti0.48)O3 (PZT) capacitors, LSMO/PZT/LSMO, LSSO/PZT/LSSO, LSSO/PZT/LSMO, and LSMO/PZT/LSSO, have been grown epitaxially on (001)SrTiO3 substrates, and their structure, switching, fatigue, and optical properties were investigated. Strikingly, contrary to the LSMO/PZT/LSMO capacitors, those having the n-type electrode show poor fatigue resistance especially at lower driving frequencies, which was further confirmed by using another n-type oxide electrode, SrTi0.9Sb0.1O3. The results suggest that with a depletion layer at the PZT/LSSO interface, charge accumulation and injection during switching may be responsible for the fatigue. [ABSTRACT FROM AUTHOR]

Conductive and transparent La0.07Sr0.93SnO3 (LSSO) films were employed as electrodes for the fabrication of epitaxial Pb(Zr0.52Ti0.48)O3 (PZT) ferroelectric capacitors. Due to a negligible lattice mismatch between LSSO and PZT, the LSSO/PZT/LSSO heterostructures grown on SrTiO3(001) substrates show excellent single-crystalline quality as revealed by high-resolution x-ray diffraction and are transparent with transmittance comparable to that of pure SrTiO3(001) substrates at the wavelength of 400–2500 nm. These capacitors show square polarization–electric field hysteresis loops but smaller polarization, larger coercive field, and especially poor fatigue resistance, in sharp contrast with those observed for the conventional epitaxial all-oxide PZT capacitors. [ABSTRACT FROM AUTHOR]

A solution process was used to grow SrTiO3 (STO) buffer layers on LaAlO3 (LAO) and biaxially textured Ni substrates by spin coating technique. The epitaxial STO film obtained has strong cube texture and uniform microstructure. A metal organic decomposition process using trifluoroacetate precursors was applied to deposit YBa2Cu3O7-δ (YBCO) thin films on these buffer layers. The YBCO/STO/LAO was biaxially textured and the TConset and ΔTC is 90.1K and 2.7K, respectively. [ABSTRACT FROM AUTHOR]

Pd films deposited at room temperature have been found to grow epitaxially on GaN grown by metalorganic vapor phase epitaxy (MOVPE). The Pd films were deposited on GaN substrates cleaned by chemicals only, and in a conventional e-beam evaporation system with a vacuum of ∼1×10-7 Torr. MeV 4He backscattering spectrometry and the Read x-ray camera were used to evaluate the Pd films. The effects of various chemical etchants—such as aqua regia, HCl:H2O, and HF:H2O—on the epitaxial quality of the Pd films have also been investigated. Ni and Pt films deposited on GaN in a similar manner were also found to be epitaxial. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Droplet impact onto a substrate usually embedded the air film at the droplet/substrate interface. However, an in-depth understanding of the migration of air film and its influence on crystallization of supersonic droplet is still lacking. In this contribution, the high pressure of supersonic impingement effectively promoted the air solubility and broke up, resulting in the diameter of air bubble significantly reduced by one-sixteenth compared to the subsonic impingement. The thin air film was not insufficiently affected the heat diffusion and caused the formation of some amorphous films around nano-sized pores. The final height and width of columnar grains were approximately decreased by one-quarter and a half than that of flattened subsonic droplet. The intersection interface of splats atomically reconstructed and formed the partially epitaxial growth of [ 2 2 ‾ 0 ] direction of columnar grains, which essentially improved the cohesion property. • Supersonic impingement effectively promoted the air solubility and broke up. • Air bubble reduced by one-sixteenth compared to the subsonic impingement. • Thin air film was not insufficiently affected the heat diffusion. • Some amorphous films formed around nano-sized pores. • Final height and width of columnar grains were decreased by one-quarter and a half. [ABSTRACT FROM AUTHOR]