Properties of Gallium in Porous Glass

• Main Authors: Wur, Ching-Shuei, 吳清水
• Other Authors: Chung Tien
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/43278455037680020162

博士 === 國立成功大學 === 物理學系 === 85 === We have studied the physical properties of gallium microparticles embeded in porous glass .Near the temperature of superconducting phase transition,the main pattern of the X-ray does not fit in with any previously repoted phase of gallium .Even though sample resistance had two-stage superconducting phase transition correspond to 7 K and 6.3 K, but from the magnetic measurement there is only one superconducting phase transition at 6.3 K~6.4 K.Sample show complete diamagnetic behavior as whole volume were the same material. Magnetic moment had a abrupt change at 4.5 K to 4.4 K as sample cooling in magnetic field . We suggest that there was phase transition correspond to vortex lattice freezing. Temperature hysteresis between melting and freezing of vortex were observed. Magnetic hysteresis at high field range showed that gallium micropartiles formed grain by strong coupling. Magnetic hysteresis at low field range seemed that grains were coupled by Josephson weak links and sample behavior as a granular superconductor.