저온 주사 레이저 및 홀소자 현미경을 이용한 YBCO 선재의 패턴에 따른 국소적 특성 분석: Analysis of the local superconducting properties in YBCO coated conductor with striation using low temperature scanning laser and Hall probe microscopy

by Mu Yong Kim (MS Candidate)

Wednesday Nov 26, 2014, 4:40 PM → 5:10 PM Asia/Seoul

119호 (제1과학관)

It is important to understand local superconducting properties of YBCO coated conductor for its application. There are several methods to measure critical temperatures or current densities of coated conductor. Those ways give global properties of whole sample, but they cannot give information of the local properties. In this study, we investigated local superconducting properties of YBCO coated conductor with striation using Low Temper- ature Scanning Laser and Hall Probe Microscopy (LTSLHPM). The distribution of local critical temperatures of a three bridge sample was analyzed from experimental results of Scanning Laser Microscopy (SLM) near the superconducting transition temperature. The local current density and the local magnetization in the sample were investigated from measuring local magnetic field by using Scanning Hall Probe Microscopy (SHPM). According to our experimental results, we investigated ‘filament effect’ which indicates the rounded distribu- tion of the current density in the three bridge sample and the local magnetization loss related to local charac- teristic magnetic field of 𝑏𝑓.

Thesis Advisor: Prof. Hyeong-Cheol Ri