Superconducting Materials [part.1]

daily-science (59)in #science • 7 years ago

Superconductors are materials that have no obstacles but have flowing current and energy below a certain temperature. A conductor may be a conductor, a semi conductor or an insulator at room temperature, but may be a superconductor at critical temperatures. The critical temperature itself is the temperature at which the conductivity changes into superconductors

Superconductors can conduct current even in the absence of a voltage source. Characteristics of a Superconductor material is a magnetic field in a superconducting value of zero and undergoes a meissner effect. The resistivity of a material is zero if it is below its critical temperature.

In the principle of a generator, a conductor driven in a magnetic field, its induced current will flow into the conductor, but the resulting current leads exactly opposite the field so that it can not penetrate the superconductor which eventually causes the magnet to float, but if the magnetic field is too large, the superconductivity will disappear.

In the superconductor the electric current flows rapidly without loss of energy, because the absence of obstacles caused by the electron pair named cooper pair in the superconductor. Coupled cooper pair flow as an entity, to issue one cooper pair, electrons must be driven to higher quantum energy which causes the lack of energy to engage collisions with metal ions.

Superconductors based on their physical characteristics consist of 2, namely Type I when the transition phase is 1, and Type 2 if the transition phase is in order of 2. Based on the explanation of the theory that can be given, the Conventional Superconductor can be explained by BCS theory (superconductivity is a microscopic effect because the condensation of the electron pair becomes condition of boston). Unconventional superconductors are not based on BCS theory. Superconducting critical temperatures below 77 Kelvin is a low-temperature superconducting cooling made with liquid hydrogen. Superconductor above the critical temperature above 77 Kelvin is a high-temperature superconducting cooling using liquid nitrogen. High-temperature superconductors are better than low temperatures, because liquid nitrogen is cheaper and easier to obtain than liquid hydrogen

Superconductor itself was first discovered by the Dutch physicist Heike Kamerlingh Onnes, from the University of Leiden in 1911. On July 10, 1908, Onnes successfully melted helium by cooling to 4 Kelvin. Then in 1911, Onnes began studying the electrical properties of the metal at very cold temperatures. Onnes estimates that the obstacles will disappear in that state. Onnes's experiment is to stream the current on a very pure mercury wire and then measure its resistance while lowering its temperature. At 4.2 Kelvin, it was found that the resistance suddenly disappeared but the current flowing through the wire remained. In the absence of obstacles, the current can flow without loss of energy. The Onnes experiment by passing the current on a superconducting coil in a closed circuit and then plucking the current source and measuring the current one year later turns the current still flowing. This phenomenon is then by Onnes is given the name of supercondutivity. For his discovery, Onnes was awarded the Nobel Prize in physics in 1913.

In 1941, niobium-nitride has been found for superconductors at a temperature of 16 degrees Kelvin. In 1953, vanadium-silicon showed superconductive surplus at 17.5 degrees Kelvin.

In 1962, scientists at Westinghouse developed commercially wired superconductors. The wire is a mixture of niobium and titanium metal (Nbti). High-Energy, Particle-Accelerator The electromagnet was made from a copper-clad niobium-titanium which was later developed at Rutherford-Appleton Laboratory, England, and was piloted in Fermilab Tevatron, USA, in 1987 at the speed of the superconducting pedals.

In 1980 Danish researcher Klaus Bechgaard of the University of Copenhagen with 3 members of France successfully synthesized the organic superconducting material (TMTSF) 2PF6, which had to be cooled at 1.2Kelvin.

In 1986, Alex Miller and Georg Bednorz, a researcher at IBM Research in Rischlikon, Switzerland, succeeded in making ceramics consisting of elements of Lanthanum, Barium, Copper, Oxygen, which are superconducting at 30 Kelvin temperatures, while ceramic has been known as an insulator at room temperature .