|
Structural Anomalies of Bi-2223 Phase in the Temperature Range of 8-305K
DONG Cheng, WU Fei, CHEN Hong, CHE Guangcan, LI Jingwei, FAN Yongxin, ZHAO Zhongxian
Chin. Phys. Lett. 1994, 11 (8):
494-497
.
A nearly single-phased Bi-2223 sample with Tc 108K was studied by low-temperature powder x-ray diffraction. Several discontinuous changes of lattice parameters are observed around 245, 160, 125,100 and 20K. The most pronounced anomalies occur dose to the superconducting transition temperature. Our observation indicates that electron-lattice interaction is quite strong near Tc.
|
|
Giant Magnetoresistance Effect in Melt Spun CoCu granular Alloys
LI Min, ZHAO Xuegen, ZHAO Tongyun, ZHAO Jiangao, SHEN Baogen, CHAI Weiping, GU Yousong, MAI Zhenhong, MEI Liangmo
Chin. Phys. Lett. 1994, 11 (8):
510-513
.
granular magnetic CoxCu1-x(x= 0.05 - 0.5) alloy ribbons were prepared by melt spinning method, and the structural, magnetotransport, magnetic properties and the effects of annealing on these properties were studied by x-ray diffraction, vibrating sample magnetometer, magnetoresistance measurement at room temperature. Giant magnetoresistance was observed over a broad range of Co concentrations with a maximum magnetoresistance (MR) ratio of 7.8% (at x = 0.20 and 500°C annealing) under a magnetic field of 20kOe. The MR ratio increases with the annealing temperature and reaches a maximum at about 500°C and then drops. The dependence of MR and magnetization on magnetic field for various granule parameters were studied by controlling the nucleation and growth of Co granules.
|
17 articles
|