DETECTION OF MAGNETIC INTERNAL CHARACTERISTIC OF SUPERCONDUCTOR, DETECTOR AND THIN-FILM MEMBER FOR DETECTION

摘要

PURPOSE:To easily and simply recognize the internal magnetic characteristics of a superconductor by bringing a magnetic thin film of a striped magnetic domain structure with which the direction of spontaneous magnetization is perpendicular to the film plane into tight contact with the same and irradiating the film with polarized light from above. CONSTITUTION:The thin-film member 2 is deposited with the magnetic thin film 3 having the perpendicular magnetization and the striped magnetic domain structure at least on the lower surface thereof. A sample 1 of the superconducting material which is a specimen is imposed on the prescribed position of a sample holder 4 and the member 2 with the surface of the thin film 3 positioned to face downward is brought into tight contact with this sample from above. The sample is thereafter inserted into a cryostat 7 and is cooled by low-temp. gaseous helium. The temp. thereof is monitored and controlled by using a thermometer 5 and heater of the holder 4. A magnetic field is impressed to the sample by an electromagnet 9 and the magnitude of this magnetic field is measured by a Hall element 6. The magnetic characteristics in the sample 1 are detected from the magnetic domain pattern corresponding to the internal magnetic flux distribution appearing in the thin film 3 when irradiated with the polarized light with a polarization metallographic microscope through a peep window 8 atop the cryostat 7.