[15a-D63-1~8] 11.1 Fundamental properties

[15a-D63-7] Microwave surface resistance of YBCO thin films with introducing artificial pins under high magnetic fields

〇Shigetoshi Ohshima¹, Naoki TAKANASHI¹, Yuzuru NARITA¹, Atsushi Saito¹ (1.Yamagata Univ.)

Keywords:high-temperature superconductor, microwave surface resistance, positron annihilation lifetime spectroscopy

We introduced artificial pins by ion irradiation, neutron irradiation in the YBCO thin film, and examined the reduction of the microwave surface resistance (Rs) under a high magnetic field. We have found the effectiveness of the introduction of artificial pins to reduce the Rs. However, it was very difficult to assess the form of artificial pins, which were formed by ion and neutron irradiations. Since the state of the lattice defects could be found clearly by positron annihilation lifetime spectroscopy, therefore we report the results of the Rs under high magnetic field and positron annihilation lifetime spectroscopy.