Meissner Effect Two Easy Experiments Showing Meissner Effect CWhen a superconducting sample is cooled below the magnetic field (ie. lines of the induction b)are quid nitrogen is added to a reservoir beneath the superconductor. (The ushed out peroonductor is actually just out of of the cup )A maller magnet levitates about a A superconductor is a perfect diamagnet! centimeter above it B Three Barriers of Superconducting Materials Critical Magnetic Field wA sufficiently strong external magnetic field can destroy the superconducting state 素 Jc High Tc(critical temperature) ohase diagram of I experimental High Je (critical current density) Application Uses of Superconductors [Levitation wire MagLev trains have been under development in Japan for the past two decades rgy loss by ahe train floats above the track using superconducting High voltage needed Wire with superconduct magnet dThere's no friction between the train and the"rail so les E Wire with superconductor energy is lost and the train can reach much higher speeds No energy loss No high voltage needed. 戀 Storage of electricity. Cut end of superconductor4 Meissner Effect When a superconducting sample is cooled below Tc in the presence of an external magnetic field, the magnetic field (i.e., lines of the induction B) are pushed out. A superconductor is a perfect diamagnet ! Two Easy Experiments Showing Meissner Effect Liquid nitrogen is added to a reservoir beneath the superconductor. (The superconductor is actually just out of sight beneath the rim of the cup.) A smaller magnet levitates about a centimeter above it. Three Barriers of Superconducting Materials High Tc (critical temperature) High Hc (critical magnetic field) High Jc (critical current density) Critical Magnetic Field A sufficiently strong external magnetic field can destroy the superconducting state critical magnetic field phase diagram of I￾type superconductor experimental data Application wire Existing wire - Energy loss by resistance - High voltage needed Wire with superconductor - No energy loss - No high voltage needed. - Storage of electricity. Cut end of superconductor wire Wire with superconductor Uses of Superconductors [Levitation] “MagLev”trains have been under development in Japan for the past two decades The train floats above the track using superconducting magnets. There’s no friction between the train and the “rail”so less energy is lost and the train can reach much higher speeds