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Investigates the epitaxial buckminsterfullerene (C[sub 60]) films grown by molecular beam deposition in cadmium fluoride surfaces. Formation of stacked hexagonal layer overgrowth in C[sub 60]; Observation of structural phase transitions in fullerenes; Influence of surface steps on epitaxial growth.

(Na0.5Bi0.5)0.87Pb0.13TiO3 thin films have been prepared on Pt/Ti/SiO2/Si and Bi2Ti2O7/Si substrates using a metal organic decomposition method. The electrical measurements were conducted on metal-ferroelectric-metal or metal-ferroelectric-insulator-semiconductor capacitors. As Bi2Ti2O7 is an effective diffusion barrier, the leakage current and memory properties of (Na0.5Bi0.5)0.87Pb0.13TiO3/Bi2Ti2O7/Si are relatively improved. The polarization-electric field and capacitance-voltage measurements of (Na0.5Bi0.5)0.87Pb0.13TiO3 on Pt show good ferroelectric properties. The three phase transitions in (Na0.5Bi0.5)0.87Pb0.13TiO3 can be recognized by the change of capacitance with temperature. [ABSTRACT FROM AUTHOR]

The phase transition was electrically investigated in (100)-oriented BaTiO3 thin and thick films deposited on Si substrate using double alkoxide solutions. Changes of the dielectric constant as a function of temperature in the range of -200–200 °C indicate that the transition from paraelectric to ferroelectric phase takes place around at 100 °C instead of 130 °C for single crystals. The broad peak of the dielectric constant shifted to lower temperatures and the behavior was associated with the crystallinity, orientation degree, and microstructure of the films. A highly (100)-oriented columnar BaTiO3 thin film with thickness of 280 nm exhibited two transitions at 0 and 100 °C from orthorhombic to tetragonal and tetragonal to cubic, respectively, while the 1 μm thick BaTiO3 film with a combined structure consisted of columnar and granular grains showed a transition at 105 °C. [ABSTRACT FROM AUTHOR]

Tight-binding molecular dynamics simulation is performed for a Si adatom on the surface containing the {311} facet and the Si(100) surface to reproduce and explain the behavior of the {311} facet in the selective epitaxial growth of Si(100). In the simulation the adatom is observed to diffuse from the {311} facet to the Si(100) surface along the pathway of a trough between the dimer rows on Si(100) surface. By the tight-binding total energy calculation, it is also clarified that adatoms easily diffuse to the Si(100) surface because, after the adatom surmounts the first energy barrier to diffuse to the step edge near the {311} facet, there is no additional Schwoebel barrier and the other energy barriers gradually decrease to the top of the dimer row of Si(100). The pathway of the trough between dimer rows on the Si(100) surface is found to be energetically more favorable than the direct pathway to the dimer row from the tight-binding total energy calculation. Our tight-binding molecular dynamics simulation elucidates the mechanism responsible for the behavior of the {311} facet in the selective epitaxial growth of Si(100). [ABSTRACT FROM AUTHOR]

Pure Bi4Ti3O12, ceramics were prepared using the conventional solid-state reaction method and their dielectric properties were investigated. A dielectric loss peak with the relaxation-type characteristic was observed at about 370 K at 100 Hz frequency. This peak was confirmed to be associated with the migration of oxygen vacancies inside ceramics. The Cole-Cole fitting to this peak reveals a strong correlation among oxygen vacancies and this strong correlation is considered to commonly exist among oxygen vacancies in ferroelectrics. Therefore, the migration of oxygen vacancies in ferroelectric materials would demonstrate a collective behavior instead of an individual one due to this strong correlation. Furthermore, this correlation is in proportion to the concentration and in inverse proportion to the activation energy of oxygen vacancies. These results could be helpful to the understanding of the fatigue mechanisms in ferroelectric materials. [ABSTRACT FROM AUTHOR]

The leakage characteristics and dielectric properties of Pt/(Ba,Sr)TiO[sub 3]/Pt thin-film capacitors were found to be remarkably sensitive to the postannealing temperature in oxygen and nitrogen atmosphere. High leakage currents and low-frequency dielectric relaxation were found in as-deposited capacitors after they had been postannealed in nitrogen at 550 °C and subsequently annealed in oxygen at 350 °C. Such results are related to the mobile oxygen ions and oxygen vacancies accumulated in the (Ba,Sr)TiO[sub 3] films. The chemical process of the formation of charged oxygen ions during postannealing is proposed. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Details a method to smooth the rough surface of GaAs microstructures based on the nucleation process for atomic layer epitaxy which involves the self-limiting two-dimensional island formation. Application of the method to smooth the (111)A surfaces of chemically etched V-grooved GaAs structures.