A recently developed crystal based continuum model for twinning and phase transformations is successfully applied to Dauphiné twinning and the α (trigonal) ↔ β (hexagonal) phase transformation in quartz. Both finite element and uniform deformation simulations are performed of quartz polycrystals and several experimentally observed phenomena are qualitatively reproduced. Results are given for me...

Selective etching of SiO2 over polycrystalline silicon has been studied using CHF3 in an inductively coupled plasma reactor ~ICP!. Inductive powers between 200 and 1400 W, as well as pressures of 6, 10, and 20 mTorr were used in this study of the etch rate and selectivity behaviors for silicon dioxide, silicon, and passively deposited fluorocarbon films. Using in situ ellipsometry, the etch rat...

Coated archwires and ceramic brackets have been developed to improve facial esthetics during orthodontic treatment. However, their mechanical behavior has been shown to be different from metallic archwires and brackets. Therefore, the aim of this study was to compare the deflection forces in coated nickel-titanium (NiTi) and esthetic archwires combined with ceramic brackets. Material and Method...

The electron scattering at surfaces, interfaces, and grain boundaries is investigated using polycrystalline and single-crystal Cu thin films and nanowires. The experimental data is described by a Fuchs–Sondheimer (FS) and Mayadas–Shatzkes (MS) model that is extended to account for the large variation in the specific resistivity of different grain boundaries as well as distinct top and bottom su...

Polycrystalline materials, such as metals, are composed of heterogeneously oriented crystals. Observed crystal orientations modelled a sample from an orientation distribution function (ODF), which determines variety material properties and is therefore great interest to practitioners. Observations consist quaternions, four-dimensional unit vectors reflecting both rotation single crystal. Thus, ...