Friday, January 11, 2008

NIST's new approach to surface profiling

Stylus profilometry is the conventional way to determine surface roughness. NIST researchers have found that 2-D profilometry, typically extrapolated to provide a 3-D roughness determination, may not be accurate.

NIST’s approach uses data from a scanning laser confocal microscope (SLCM), an instrument that builds a point-by-point image of a surface in three dimensions. The data from a single SLCM image are analyzed using mathematical techniques that treat every point in the image simultaneously to produce a roughness measure that effectively considers the entire 3-D surface rather than a collection of 2-D stripes.

One early finding is that the generally accepted linear relationship between surface roughness and material deformation is wrong. The more accurate data from the 3-D analysis shows that a more complicated relationship was masked by the large uncertainties of the linear profilometers.

Monday, January 7, 2008

Hard Thin Films are Important

Hard coatings are a fascinating field of study where remarkable science is being done with extraordinary results. (see earlier posts: "Tribological Coatings..." and "PVD Hard Coatings...") The loss due to wear and corrosion in the US is estimated to be approximately $500 billion. A diamond coating can increase service lifetime for a coated article from 8 days to 85 years. The economic and environmental impact, then, can be enormous. I would be surprised if total market penetration was greater than 50%. Does anyone have specific market data? I find it remarkable, after years in the business, how difficult it can be to convince customers to use hard coatings, even though the lifetime savings can be so significant. Share your stories and ideas with us. Kudos to those of you doing the important and often overlooked work of hard coatings. The Surface Engineering Coating Association (SECA) is a valuable resource for information on hard coatings and providers.
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Friday, January 4, 2008

Science as Art

Winners from the Science as Art competition held at the 2007 Materials Research Society (MRS) Fall Meeting are beautiful and thought provoking.

Nano-Explosions: Color-enhanced scanning electron micrograph of an overflowed electrodeposited magnetic nanowire array (CoFeB), where the template has been subsequently completely etched. It’s a reminder that nanoscale research can have unpredicted consequences at a high level. (Image: Fanny Beron, École Polytechnique de Montréal, Montréal, Canada)

Red Planet: Combined 3-D representation of two images taken by scanning tunneling microscopy. The land is from an STM image of one monolayer of HATNA deposited on Au(111), and the sky is from an image of THAP/Au(111) exposed to a high background pressure of cobaltocene. (Image: Sieu Ha, Princeton University, Princeton, USA)
Beauty of Nature: SEM image of CuInSe2 film with Cu2Se (plates) and InSe (needles) crystals on the surface. (Image: Olga Volobujeva, Tallinn University of Technology, Tallinn, Estonia)

Thursday, January 3, 2008

Thin Film Solar Power - Cheaper than Coal?

Thin Film solar superstar, Nanosolar, has shipped their first panels. Their 430 MW plant in California will be the largest in the world and allow them to sell at less than $1/Watt per panel, or about $2/Watt in a complete system. According to the Energy Department, building a new coal plant costs about $2.1 a watt, not including the costs of fuel and emissions. Is this a watershed for solar energy? It may be difficult for vacuum deposited thin film solar manufacturers to compete with Nanosolar, which uses nanoparticle ink jet printing in atmosphere on metal foil, roll to roll. Their plant reportedly is costing about 15 million dollars to build, compared to about 350 million for a vacuum deposited solar cell plant. Nanosolar is tight lipped about their efficiency, but Copper Indium Gallium Selenide (CIGS) cells have reached 19.5% in the laboratory.