A model is presented that describes the pumping characteristics of St707 getter material, the evaporation rate of antimony, and the resulting partial pressure of Sb within a vacuum chamber. The results show that within the 250-450◦C range, the partial pressure of antimony ranges from 10−7 Pa to 10−2 Pa. In a limiting case where the getter efficiency is tuned to 10, 000 L/s, partial pressures ar...

Few-layer graphene films are grown using a Molecular Beam Deposition (MBD) technique in ultra-high vacuum by evaporation of atomic carbon and subsequent annealing of the samples at 800–900 °C. The graded thickness layers are grown on strip-shaped oxidized silicon substrates which are covered with 300 nm thick nickel films deposited by e-beam evaporation. The thickness of the deposited carbon la...

One-dimensional silicon nanowires (SiNWs) were prepared by electron beam evaporation in ultrahigh vacuum (UHV). The SiNWs can be grown through either vapor-liquid-solid (VLS) or oxide-assisted growth (OAG) mechanism. In VLS growth, SiNWs can be formed on Si surface, not on SiO2 surfaces. Moreover, low deposition rate is helpful for producing lateral SiNWs by VLS. But in OAG process, SiNWs can b...

Calcium-, aluminum-rich inclusions (CAIs) are often enriched in the heavy isotopes of magnesium and silicon relative to bulk solar system materials. It is likely that these isotopic enrichments resulted from evaporative mass loss of magnesium and silicon from early solar system condensates while they were molten during one or more high-temperature reheating events. Quantitative interpretation o...

We call a state “vacuum bounded” if every measurement performed outside a specified interior region gives the same result as in the vacuum. We compute the maximum entropy of a vacuum-bounded state with a given energy for a one-dimensional model, with the aid of numerical calculations on a lattice. For large energies we show that a vacuum-bounded system with length Lin and a given energy has ent...

Abstract: Different thickness of Cu2S thin films were prepared by vacuum evaporation under a pressure of 10-6 torr at an evaporation rate of 3Å /sec. Cu2S has direct band gap energy and indirect band gap energy at 1.2eV and 1.8 eV respectively. This paper presents the analysis of structural and optical properties of the Cu2S thin film by X-ray diffractometer (XRD) and UV-Vis-NIR Spectrophotomet...

Iron oxide thin films, with an α-Fe2O3 phase, were deposited by two techniques. The first was evaporation of iron in vacuum, followed by oxidation through annealing in air. The second was reactive evaporation of iron in an oxygen atmosphere. This was also followed by annealing in air. The structural, morphological and chemical properties of the films were investigated. All films were polycrysta...

This article introduces a facile nanoparticle self-assembly/annealing method for the preparation of nanoisland films. First, nanoparticle-polymer multilayer films are prepared with layer-by-layer assembly. Nanoparticle multilayer films are then annealed at ~ 500 C in air to evaporate organic matters from the films. During the annealing process, the nanoparticles on the solid surface undergo nuc...

This paper describes a vacuum-decay based evaporative leak detection procedure for vehicle fuel systems. A physical model for an evaporative system is proposed containing parts for fuel evaporation, leakage flow and canister flow. Two methods for detecting evaporative leakages based on the model is presented. Both methods can detect a 0.5 mm diameter leakage in a laboratory environment.