physics presentation superconductors
Post on 13-Apr-2017
70 Views
Preview:
TRANSCRIPT
SUPERCONDUCTORSPHENOMENON DISCOVERED
BY K. ONNES IN 1911. AND HE HAD WON NOBEL
PRIZE FOR THIS INVENTION IN 1913.
ACCORDING TO HIM "WHEN A MATERIAL IS COOLED BELOW A SPECIFIED TEMPERATURE IT TOTALLY LOOSES ITS PROPERTY OF RESISTANCE AND BECOME A SUPERCONDUCTOR".THIS SPECIFIED TEMPERATURE IS KNOWN AS CRITICAL TEMPERATURE AT WHICH A MATERIAL TURNS INTO A SUPERCONDUCTOR.
TEMPERATURE DEPENDENCE OF RESISTIVITY IN SUPERCONDUCTING
MATERIAL-:
EFFECT OF MAGNETIC FIELD-:
IN 1913 K. ONNES OBSERVED THAT SUPERCONDUCTIVITY IS DESTROYED IF A SUFFICIENT STRONG MAGNETIC FIELD IS APPLIED. THE MINIMUM MAGNETIC FIELD WHICH IS NECESSARY TO REGAIN ITS NORMAL STATE IS CALLED CRITICAL MAGNFIELD.
Meissner effect-:
IN 1933 MEISSNER OBSERVED THAT IF A SUPERCONDUCTOR IS COOLED BELOW CRITICAL TEMPERATURE CORRESPONDING TO THAT FIELD, THEN LINES OF INDUCTION ARE EXPELLED FROM THE MATERIAL . AND THIS EFFECT IS NAMED AS MEISSNER EFFECT.
BCS THEORY (explanation of superconductivity)-:
IN 1957 BARDEEN COOPER AND SCRIEFFER GAVE A THEORY TO EXPLAIN SUPERCONDUCTIVITY NAMED AS BCS THEORY SHOWS LATTICE DISTORTION
ELECTRON-LATTICE-ELECTRON INTERACTION VIA A PHOTON FIELD
HIGH TEMPERATURE SUPERCONDUCTORS-:
IN 1986 BEDNORZ AND ALEX MULLER DISCOVERED THE HIGH TEMPERATURE SUPERCONDUCTIVITY IN CERAMICS AND THEY WERE AWARDED THE NOBEL PRIZE IN PHYSICS IN 1987THEY MADE A PARTICULAR TYPE OF CERAMIC MATERIAL WHICH REMAINED A SUPERCONDUCTOR AT A TEMPERATURE AS HIGH AS 30 K. EXAMPLES OF HIGH TEMPERATURE SUPERCONDUCTOR ARE-:
APPLICATIONS OF SUPERCONDUCTORS
(1) POWER TRANSMISSION(2)SUPERCONDUCTING MAGNETS(3) FOR PROGRESS OF COMPUTER TECHNOLOGY(4) SUPERCONDUCTING QUANTUM INTERFERENCE DEVICES (SQUIDS)(5) VERY STRONG MAGNETIC FIELD
top related