b'Geophysics in the surveysNewsin production. The move is not a push,that survey being made visible on SARIG.of letters and numbers, looking for a rather it is a pull, with SA GovernmentAs indicated, we are currently workingmisplaced comma.IT external to the GSSA managing thethrough uploading a batch of surveys. WeNgaityalyaprocess. Finally, the SARIG server must beanticipate these will be available in early restarted for the changes to \x1bow through2024, before they are added to a new state(Kaurna, thank you)to production. grid product. Stay tuned! Philip Heath It can therefore take over a month fromFigure 1 (not included): a photographGeological Survey of South Australia identifying a \x1dle for upload, to the points ofof the author, staring at a screen fullPhilip.Heath@sa.gov.auHenderson Byte: Superconductorssome new developmentsA superconductor is a material that conducts direct current with no electrical resistance. This lack of resistance supports very high currents without loss, and makes superconductors very attractive for use in power transmission. Also, the persistence of current in a closed loop can be used in various applications to make large permanent magnets. For example, todays Magnetic Resonance Imaging (MRI) machines use superconductor magnets to achieve a magnetic \x1deld strength 30 000 times stronger than the Earths \x1deld. Superconductors also make for highly e\x1ccient electronics with extremely high levels of performance.An important feature of superconductors, which con\x1drms the existence of the state, is that they expel the magnetic \x1deld from within the material and also do not allow the magnetic \x1deld to penetrate. This phenomenon in superconductors is called the Meissner e\x1eect. This makes them powerful electromagnets, some with the ability to levitate trains. Superconducting circuits are also a promising technology for quantum computing because they can be used as qubits, the basic units of quantum processors.However, until recently, the ultra-low temperatures (close to absolute zero, 0 Kelvin) and ultra-high pressures (104 bar) necessary to achieve the superconducting state makes it inconvenient to implement. An ideal superconductor would be at room temperature and pressure. If such a superconductor could be economically mass-produced, it could revolutionise electronics. Despite decades of intense research e\x1eorts, such a state is yet to be realised.In recent decades, researchers have developed a class of so-called high-temperature superconductors, de\x1dned as materials with a critical temperature, T c(the temperature below which the material behaves as a superconductor) above 77 K (196.2 C), which is the boiling point of liquid nitrogen. They are only high-temperature relative to previously known superconductors, which function at even colder temperatures.New room-temperature superconductors promise to change that. As the name suggests, room-temperature superconductors dont need special equipment to cool them. Some do need to be pressurised, but only to a level that can be achieved by using strong metallic casings.In March this year, eleven researchers at the University of Rochester, New York, USA announced in Nature a new material that is a superconductor at room temperature. It is a synthesised compound of nitrogen-doped lutetium hydride exhibiting super conductivity at a critical temperature, T c, of 21oC (294 K). While at room temperature, the pressure required is still high at 104 bar, and would restrict the use of this superconductor (see Dasenbrock- Gammon etal., 2023. Nature, 615, 244250).However, subsequent published criticism of this research, which claims that it does not present evidence for true superconductivity, has resulted in this paper being retracted from Nature in November, 2023.In June this year, two research teams in China, one led by Jianjun Ying at the University of Science and Technology of China and the other led by Changqing Jin at the Chinese Academy of Sciences, published their work together on the production of a single element superconductor with the highest critical temperature to-date of -237oC (36 K) This was using Scandium (Sc) compressed between two diamonds. While much below room temperature, the T cis comparable to that of classic multi-element superconductors. However, it is still at a pressure of 104 bar. (See Physical Review Letters,130, 256002).A more recent development in July this year, by Hyun-Tak Kim and colleagues at William and Mary College in Virginia, USA, is the formulation of a multi-element superconductor at room temperature and pressure. The synthetised material, called LK-99, is a modi\x1ded lead apatite crystal and its resistance is near zero at 300 C (See New Scientist, 5 August 2023). The conductor exhibits the Meissner e\x1eect when a millimetre-sized sample of LK-99 is placed on a magnet. This is illustrated in a still from a video in the above New Scientist paper, page 10. Only one edge of LK-99 levitates, due to only that part being superconductive. Two papers, not peer reviewed, reporting this development, are doi.org/kk42 and doi.org/kk43. The latter is by Kims colleagues at Korea University in South Korea.While the above development is considered by many to be an important breakthrough in the quest to have easy-to-use superconductors, some are sceptical of the results from LK-99 and claim it is too early to say that the evidence of superconductivity is certain.Clearly this is a space to be watched!Roger Henderson rogah@tpg.com.au21 PREVIEW DECEMBER 2023'