Archive for the ‘Properties’ Category
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March 8th, 2010
Colliding gold creates new matter
A never-before seen particle, called an anti-hypertriton, has been created for the first time during experiments at the Relativistic Heavy Ion Collider (RHIC) on Long Island, New York. Particles of gold were collided just short of the speed of light (186,000 miles per second) and more than 100 million collisions were made to collect the data. The matter created during the experiments is believed to have been in existence immediately after the creation of the universe – the so-called “Big Bang”.
Unfortunately, we’re a bit short of particles physicists here at the WGC, so if you’d like to read more the work is available here as a science advanced online publication.
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March 1st, 2010
Black gold electroplating
NEW Black gold electroplating on the market!
There is considerable interest in black colour effects on gold jewellery. To date, this has usually been achieved by electroplating black rhodium or black ruthenium layers on carat gold items or by oxidation of special carat gold alloy compositions (see special gold colours on utilisegold.com ) Whilst black rhodium or ruthenium offer satisfactory black coatings, there has been a desire to have a real black gold. At last, Wieland GmbH, Germany, have produced one, called NEOPAL. This is claimed to be “an innovative new decorative surface treatment which deposits a high quality layer of deep black gold plating”. This is a ‘first’ in gold electroplating solutions. I have a ring plated in Neopal; it is a lovely bluish black colour that is very attractive. Neopal is easy to use, with a layer thickness of <10 microns, and has uniform deposition characteristics with a hardness of 60 – 75 HV. For further information, contact Wieland – www.wieland-international.com
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February 12th, 2010
Gold for good – a new article from the WGC
Yesterday we released a new publication written by the World Gold Council and Cientifica called ‘Gold for good – gold and nanotechnology in the age of innovation’. The article, which is freely available on both the WGC and Cientifica websites, discusses the past, present and future of gold-based nanotechnology, focusing on key areas in medicine, the environment and technology.I am attending the 2010 Nanotech Japan event in Tokyo next week where I will be launching the article, and will follow this with a trip to the ACS spring meeting in California towards the end of March. Feel free to drop me a line if you are attending either event, I’d be happy to discuss any aspect of the WGCs activities, including our funding and investment programmes.
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January 22nd, 2010
Fault current limiters using gold-alloy coatings
Some months ago I blogged on the use of superconductors for fault current limiters devices. These require the use of a metallic shunt top layer to give a degree of thermal and electrical protection should a fault in the superconducting tape develop. This metallic layer is typically 50-100nm thick and must be resistant to oxidation at the high temperatures which can arise during both processing steps and in service during current overload situation. It must also serve as a barrier to prevent ingress of moisture into the YBCO superconductor. This story (although from last year – I’ve only just been told about here in Japan) shows the use of silver-gold alloy layers in a practical example of this technology.
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December 21st, 2009
New Book – Gold Science and Applications
I’m excited to announce that a new book ‘Gold – Science and Applications’ has now been published.
There have been many excellent books written on certain aspects of the science and technology of gold, most notably the book of the Hanau gold conference, held in 1996 (“Gold. Progress in Chemistry, Biochemistry and Technology”, edited by Hubert Schmidbaur and published in 1999) and there are several new books covering specific sectors of gold science e.g. on catalysis, chemistry and nanotechnology (see here). However, for those seeking a broader reference source on gold and covering all technical sectors, the most appropriate book on gold, Gold Usage by Bill Rapson and Theo Groenewald, was published over 30 years ago in 1978. The world of gold has changed considerably since then. A few years ago Chris Corti and I believed it was time for an updated book that reflects the more recent developments.
With the co-operation of some of the leading experts in their field, we have attempted to produce a book that is a worthy successor to ‘Rapson’ and to provide an authoritive source of information. We have attempted to cover all the main scientific areas as well as the main areas of application. In some cases this has required some very detailed scientific chapters; other fields require less specific detail and have focused more on the practical application. In addition, to help readers place this science and technology in the context of a much wider gold market, a chapter on the supply, demand and pricing of gold is included. Taken together, our aim for the book is to appeal to both those working in academia and industry.
If you are interested, your can read more and purchase it here .
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November 17th, 2009
Google Library and Gold Usage
Yesterday’s post got me thinking about the various books that have been published on gold and specifically those concerned with the science and technology of gold. The ‘classic’ reference book is Gold Usage by Bill Rapson and T. Groenewald (Academic Press, 1978, ISBN 0-12-581250-7). It is absolutely packed full of high quality chapters on both the fundamental technical properties of gold and the specific applications. The big problem with this book is it is out of print, having been published in the 1970’s. Could Google Library be the answer to this problem? This article published in today’s Times describes the background to Google’s plan to digitise out of print materials like Gold Usage. There are both merits and problems with Google’s approach (which I won’t delve into) but if it does materialise, we will be sure to link to the various chapters. -
November 5th, 2009
Which gold conductor?
Yesterday afternoon at IMAPS 2009, we heard from Samson Shahbazi of Heraeus Materials Technologies on the subject of ‘Cost Effective Use of Gold in Thick Film Conductors’. Samson explained that designers of hybrid circuits had a choice between three basic classes of gold conductor; gold powder, flake and resinates. He went on to explain the relatives benefits of each. What was really interesting was that in response to a question from the audience along the lines of ‘what cheaper alternative materials and technologies are becoming available to replace gold in this application?’, the response was ‘there is nothing that offers anything like comparable performance to gold’. This looks like one application for gold that isn’t going to disappear in the short-term…..
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October 27th, 2009
Ford Motor Company and Au Nanoclad™
Some weeks ago I posted on the subject of fuel cell separator plates and how gold-coated stainless steel was proven to be the best material for this application, in terms of conductivity and durability. The only issue was cost – what was need was a reduced thickness gold coating, still displaying the performance of a thicker coating.
Well, according to a presentation to be made at Fuel Cells Durability & Performance 2009 (December 8-9, 2009 · Alexandria, VA USA) The Ford Motor Company is to present on ”Nanometer Range Gold Coated Stainless Steel for Automotive Polymer Electrolyte Membrane Fuel Cell Bipolar Plate”.
Apparently, Ford is currently developing metallic bipolar plate technology with thin gold-coated stainless steel (under the brand name Au Nanoclad™) provided by Daido Steel. They claim that the use of nanometer range gold coating delivers the required electrical conductivity and corrosion resistance with least impact of cost of gold. Additionally, gold-coated stainless steel shows anodic passivation, thereby exhibiting robustness towards coating defects including surface scratches during the manufacturing of the bipolar plate. Apparently the presentation at the conference will include the ex-situ and in-situ testing data for this material.Looks like a potentially fantastic new use for gold if the fuel cell market takes off…..
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October 21st, 2009
The world’s smallest test tube…?
I love reading about new nanotechnology breakthroughs, and the journal science is often a good place to look for such articles. Indeed there’s a great paper in the most recent issue penned by a team at the University of Texas at Austin. What the group, led by Brian Korgel, have done is fashion a nanoscale test tube out of a ultra-thin carbon shell. This nano test tube contains a gold nanocrystal on the end of a germanium nanowire.
Whilst this is a pretty unusual experimental set up, no question, it has allowed the team to closely study physical transformations in materials. Because the gold and germanium are both confined by the carbon shell, changes in volume and interfacial area are prevented on heating and cooling. Using electron microscopy, the fundamental heating, cooling and crystallisation processes of the gold and germanium could be observed – they even made a couple of movies of the melt/diffusion events!
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October 14th, 2009
Powder Metallurgy & Gold
I’ve just received a complimentary e-version of the International Journal of Powder Metallurgy “Precious Metals” Focus Issue. This Journal is published 6 times a year, bringing the latest news in the powder metallurgy and particulate materials industries.In his editorial, Alan Lawley states:
Precious metal powders find wide commercial applications because of their unique characteristics and properties, including thermal/electrical conductivity, corrosion resistance, solderability, and stability at high temperatures, coupled with reliability. Applications include conductive adhesives, dental restorations, catalysts, and sensors to monitor temperature and corrosion, and to detect gases. In comparison with ferrous powder metallurgy (PM), particulate precious metal science and technology receives limited exposure and press in industry news coverage. This “Focus Issue,” coordinated by Pierre Taubenblat and Joe Strauss, traces the history of particulate precious metal technology and gives an overview of market dynamics and current and near-term industrial applications. Comprehensive reviews of precious metal powder production methods and the manufacture of dental restorations are also included.
With so much happening in the application of gold in nanotechnology, catalysis and chemistry, it is good to see the metallurgical applications of gold being highlighted….
Trevor Keel
Chris Corti
Richard Holliday
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