Historical Account of Superconductors

Josephson won the Nobel Prize in Physics for his work which is known today as the 'Josephson Effect' and has been applied to many electronic devices, including SQUID (an instrument capable of detecting the weakest magnetic fields).

In 1964, the suggestion of organic superconductors was announced by Bill Little of Stanford University which was then successfully synthesised in 1980 by Danish researcher Klaus Bechgaard of the University of Copenhagen and 3 French team members.

At 30K, the highest know temperature of the time, a brittle ceramic compound was found to be superconductive. This discovery was interesting to science as ceramics are normally insulators. The lanthanum, barium, copper and oxygen compound that Alex Muller and Bednorz synthesised behaved in a fashion not fully known aware to science.

In the United States, high-energy particle-accelerators from the Rutherford-Appleton Laboratory were employed in a superconducting accelerator at the Fermilab Tevatron.

In January of 1987 a research team at the University of Alabama-Huntsville substituted yttrium for lanthanum in the Müller and Bednorz molecule and achieved an incredible 92 K Tc. For the first time a material (today referred to as YBCO) had been found that would superconduct at temperatures warmer than liquid Nitrogen - a commonly available coolant.

The first company to capitalise on high-temp superconductors was Illinois Superconductor which was formed in formed in 1989. The company introduced a depth sensor for medical equipment that had the ability to operate at liquid nitrogen temperatures, which is approx. 77K.

Highest temperature superconductor known to date was patented by Korean scientists; the material is known as mercury thallium barium calcium copper oxide.

Researchers discovered that at a temp. very near to absolute zero, the alloy of gold and indium existed simultaneously as a superconductor and a natural magnet.

In the year 2000, science saw the first high-temperature superconductor that doesn't contain any copper.

In 2001, the discovery of the first all-metal perovskite superconductor was found.

For many decades sitting on laboratory shelves, a material was found to be an intriguing new superconductor. Japanese researchers measured the transition temp. of magnesium diboride at 39K, which is far above the highest critical temp. of any elemental or binary alloy superconductors.

Superconductors.org discovered that increasing the weight ratios of alternating planes within the layered perovskites can often increase Tc significantly. This has lead to the discovery of more than 140 new high-temperature superconductors.

The most recent of superconductors to be discovered is the 'pnictides'; an iron-based superconductor first observed by a group of Japanese researchers in 2006.

In the future, as scientists figure out how to achieve superconductivity at higher temperatures, in a wider range of materials, HTS (high-temp superconductors) is likely to become an increasingly exciting and lucrative technology.

The most widespread practical use for superconductors in the present is in body scanners, based on a cunning bit of science called NMR (nuclear magnetic resonance).