A chance happening four years ago at an IBM laboratory in Reuschlikon, Switzerland, led to the breakthrough of a problem that has puzzled physicists for decades. Swiss scientist, Professor Alex Mueller, and his German protege Georg Bednorz, were trying to find a cheap, simple substance to conduct electricity without resistance. At the suggestion of Muellers’ old IBM boss, Professor Thomas, they began their research on a ceramic that makes a better insulator than conductor. Thomas theorised that treating certain insulators may cause the tightly bound electrons to leave their atoms. They would then be free to move smoothly from atom to atom, propelled by strong internal forces. He reckoned they may conduct without the expensive liquid helium cooling normally associated with superconductivity. Mueller, well known for his studies into the workings of electrical materials used in IBM products, knew a lot about the most likely materials – metal oxides formed when a metal is left in a hot oven long enough to react with air.
Houston
By the end of 1985 the pair were no nearer their goal, and it was by a stroke of luck that Bednorz came across the work of two University of Caen scientists when he was searching for new leads in the lab library. This led them on to work with Copper compounds rather than Nickel. Working with a Copper Oxide laced with Barium and Lanthanum, Bednorz saw the normal resistance of his superconducting sample drop by half at temperatures below minus 262` Celsius (minus 127`C Fahrenheit). This, they managed to push up to minus 250`C, then a previously unknown 238`C. Frontiers were pushed further forward in February of this year, when Paul Chu, a superconductor specialist from the University of Houston, persuaded the material to superconduct at minus 178`C – warmer than liquid Nitrogen. This is a far cheaper coolant than Helium and meant that liquid Helium and its expensive thermos cooling systems were no longer necessary. This left the way clear for researchers to go on to develop applications for the new-found superconductivity. Although nothing significant has yet come out of the worldwide goings on, in the US companies are springing up to cash in on the rapidly developing industry. Quite apart from five university-industry consortia being established for research and development, greenfield venture start-ups with names like American Superconductor Corp and Conductor Technologies Inc are proliferating. American Superconductor was founded by a team from the Massachusetts Institute of Technology in April of this year. Here, two researchers, Gregory Yurek and John Vander Sande, are working on a process to make wire and other products from malleable, metal precursors. These have the advantage of being easier to shape before they are heated to produce superconductivity, than ceramic materials are in their final form. This is a technique other research teams, notably ones at Boston’s Northeastern University and at Argonne National Laboratory, are interested in but, as Mr Vander Sande says, a lot of work needs to be done to make the process commercially viable. Despite the possibilities recently-discovered high temperature superconductors bring (CI No 725) – levitated trains, faster computers, Nuclear Magnetic Resonance – venture capitalists are slow to follow the start-up craze, keeping all the pitfalls well in mind. No-one knows how the new materials work and as George Reichenbach, a venture capitalist with Advent International, Boston, was quoted as saying in the Wall Street Journal: If you had a good theory, you could write a patent application specifying a broad class of materials. But since we don’t know how they work, patents can only deal with specific compounds people make. He points out that even this can prove difficult as competitors can produce compounds which, although they have the same properties, vary slightly in chemical make-up and do not come under the patent. Although venture capitalists are aware that start-up companies will have to battle against larger concerns such as IBM, they expect
superconductivity to evolve mainly from university schemes. It will be a long time before anyone sees a return on their money and hard work. That’s why some prefer to invest in the companies who provide the researchers with materials and instruments. Alternatively they back university research giving them priority in licensing the patents that result. The more adventurous universities are going to the venture capitalists instead of waiting for them to make the first move. At the University of Houston – recently named as the state’s new Texas Center for Superconductivity – with the help of $4m initial funding, 200 people are to be employed in nine groups to tackle problems in pure and applied research. And Lehigh University in Bethlehem, Pennsylvania expects to raise $400,000 to establish a consortium within the next few weeks. In Berkeley, California, the Lawrence Berkeley Laboratory has been chosen by the US Department of Energy as one of four proposed research centres to assist and accelerate the commercialisation of high temperature superconductors. This follows President Reagan’s announcement of an initiative program to promote further work in the field of superconductivity. The Lawrence Berkeley centre will work on thin film applications of high temperature superconductors for radiation detectors, magnetometers, computers, sensors.
Japan
Meanwhile staff at the Japanese Ministry of International Trade and Industry are working against the clock, creating programs to bolster superconductivity research and beat the August budget deadline. Spurred on by Mueller and Bednorz, MITI found a ceramic that could conduct at temperatures even higher than 250`C, only to be knocked back into second place when the University of Houston announced superconductivity at 178`C. This caused a flurry of activity and since then Mitsubishi Electric has filed more than 130 patents while Sumitomo Electric filed 700 this year, most of them for applications. Amid the euphoria and speculation – superconductivity may be a $20,000m-a-year industry by the year 2000 but it could be five or ten years before the new superconductor finds their way into products – there comes a note of caution for those who see the technology as the answer to the chip industry’s prayer. When it comes to trying to fabricate chips from the new materials, AT&T Bell Laboratories points out that the baking process used to create the metal oxides require temperatures of 700`C to 900`C, too high for making hybrid circuits with Silicon or Gallium Arsenide. Moreover conventional vacuum deposition techniques cannot be used – the process causes oxides to lose oxygen: reduce the oxygen in a superconductor and it becomes a semiconductor or even an insulator. And no-one yet knows such fundamentals as the diectric constant, resistivity or noise figure for the new materials.
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