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Plasma deposition of beryllium carbide via magnetron sputtering

Posted on:1999-05-17Degree:Ph.DType:Dissertation
University:University of Missouri - RollaCandidate:Xie, YixiangFull Text:PDF
GTID:1461390014470105Subject:Chemistry
Abstract/Summary:
Inertial confinement fusion (ICF) is an alternative energy source with as little environmental impact as possible.; The materials of the multilayered microsphere require high energy transparency, smooth surfaces and permeability to {dollar}rm Hsb2.{dollar} Plasma-deposited coatings containing beryllium in excess of 50 atomic percent and oxygen content {dollar}<{dollar}5 atomic percent would meet these requirements for the outermost coating, the outer ablator.; Films containing a {dollar}rm Besb2C{dollar} composite with Be contents as high as 75 atomic percent (O {dollar}<{dollar} 2 atomic percent) have been deposited on a variety of substrates via magnetron sputtering of Be into a methane/argon plasma. The elemental composition was controlled by adjusting the methane/Ar flow rate ratio during the deposition process. The films were characterized by AES, XPS, XRD, ND, SEM, AFM, DTA, TGA and electrical and thermal conductivities.; The film which comes the closest to meeting the ICF capsule requirements was deposited at a {dollar}rm CHsb4/Ar{dollar} flow rate ratio of 0.1. These films (2.5 {dollar}rmmu m{dollar} thick) have a {dollar}rm Hsb2{dollar} permeation coefficient of 7.0 {dollar}rm cmsp3{lcub}cdot{rcub}cm/cmsp2{lcub}cdot{rcub}sec{lcub}cdot{rcub}cmHg{dollar} which would allow the fuel to fill the capsule in about 0.78 hours. The Vickers relative hardness to silicon is 1.1. Defect stress analysis indicates the films' tensile strength to be in the range of {dollar}10sp4{lcub}-{rcub}10sp5{dollar} psi, which meets the ICF standards for filling the capsules to a 350 atm inner pressure. The thermal conductivity is 1.95 {dollar}rm W/mspcirc C{dollar} at {dollar}25spcircrm C.{dollar} The deposition rate of the films at the methane/Ar flow rate ratio of 0.1 is 1.25 {dollar}rmmu m/day.{dollar}...
Keywords/Search Tags:Flow rate ratio, Deposition, {dollar}rm, ICF, Atomic percent, Films
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