We use laser-induced photoemission spectroscopy at 6 eV photon energy to investigate quantum well states of epitaxial Pb films on Si 111 as function of film thickness. The binding energies of the quantum well states were found in good agreement with density-functional calculations for a freestanding Pb slab. An oscillation of the work function with a period of 2 ML was observed as a function of...

The magnetic shape memory (MSM) alloy Fe70Pd30 is of particular interest for novel microactuator and sensor applications. This review summarizes the underlying physical and material science concepts for this MSM alloy system. First-principles calculations of the electronic and crystallographic structure together with combinatorial and epitaxial film studies are presented. By these complementary...

This article is focused on a fractography study of cleavage cracking at triple grain boundary junctions in freestanding silicon thin films. At a triple junction, as the crystallographic orientations of the two grains ahead of the crack are different by only a few degrees, the cleavage front advance becomes quite jerky. The crack first enters the grain of smaller boundary toughness and then turn...

The Membrane Deflection Experiment was used to test the mechanical response of freestanding thin film gold specimens. We present stress-strain curves obtained on films 0.3, 0.5, and 0.1 μm thick. Elastic modulus was consistently measured in the range of 53–55 GPa. Several size effects on the mechanical properties were observed including yield stress variations with membrane width and film thick...

Thick c-plane unintentional doped and iron-doped GaN substrates were grown by hydride vapor phase epitaxial technique on sapphire substrates. The morphology and crystalline quality of the freestanding samples show no evident degradation due to iron doping. Low-temperature photoluminescence measurements show reduction of the exciton-bound to neutral impurities band intensities with iron doping i...

A combined experimental/simulation approach has been used to characterize the underlying deformation mechanisms associated with stress-assisted grain growth in nanocrystalline Al. Strain rate sensitivity experiments on freestanding submicron thin films undergoing stress-assisted grain boundary migration have uncovered rate sensitivities up to two orders of magnitude larger than previously repor...

We report the fabrication and frequency characterization of mechanical resonators piezoelectrically actuated with aluminum nitride films. The resonators consist of a freestanding unimorph structure made up of a metal/AlN/metal piezoelectric stack and a Si3N4 supporting layer. We show that the electrical impedance of the one-port device can be used to assess the vibrational behavior of the reson...

We found that very thin carbon nanotube films, once fed by sound frequency electric currents, could emit loud sounds. This phenomenon could be attributed to a thermoacoustic effect. The ultra small heat capacity per unit area of carbon nanotube thin films leads to a wide frequency response range and a high sound pressure level. On the basis of this finding, we made practical carbon nanotube thi...

Assembly of carbon nanotubes (CNTs) in effective and productive ways is of vital importance to their application. Recent progress in synthesis of CNTs has inspired new strategies for utilizing the unique physiochemical properties of CNTs in macroscale materials and devices. Assembling CNTs by dry processes (e.g., directly collecting CNTs in the form of freestanding films followed by pressing, s...

We present a micro-electro-mechanical system-based experimental technique to measure thermal conductivity of freestanding ultra-thin films of amorphous silicon nitride (Si3N4) as a function of mechanical strain. Using a combination of infrared thermal micrography and multi-physics simulation, we measured thermal conductivity of 50 nm thick silicon nitride films to observe it decrease from 2.7 W...