Transport properties of CoSb/sub 3/ doped with magnetic impurities Fe and Ni

Author(s):  
H. Anno ◽  
H. Tashiro ◽  
K. Matsubara
2012 ◽  
Vol 501 ◽  
pp. 309-313 ◽  
Author(s):  
Siti Nurdalila Abd-Ghani ◽  
Roslan Abd-Shukor ◽  
Wei Kong

The effects of nano particles Fe3O4 addition on the superconducting and transport properties of YBa2Cu3O7-δ (YBCO) were studied. YBa2Cu3O7-δ superconductor powders were prepared by using high purity oxide powders via solid state reaction method. Nano Fe3O4 with 0.01 – 0.05 wt.% with average size 28 nm was added into YBCO. The transition temperatures (Tc) of the samples were measured by using four point probe method. The critical current (Ic) of the samples has been determined by using the 1 μV/cm criterion from 30 – 77 K. Sample with 0.02 wt.% nano Fe3O4 showed the highest Tc at 87 K. It is interesting to note the same sample also exhibited the highest Jc at 77 K up to 1683 mA/cm2. Nano Fe3O4 has acted as effective flux pinning centers in YBCO. A small amount of nano particles Fe3O4 addition has successfully improved the superconducting and transport properties of YBCO. The excessive addition of nano Fe3O4 (> 0.02 wt.%) suppressed the Tc and Jc. Overall, Jc decreases with increasing temperature (30 – 77 K) as a consequence of thermally activated flux creep. Magnetic impurities normally suppress superconductivity. However, by adding magnetic nano particles, current carrying capacity of superconductors YBCO was enhanced significantly.


2013 ◽  
Vol 27 (15) ◽  
pp. 1362036 ◽  
Author(s):  
LI LV ◽  
MIN ZHANG ◽  
ZHANTAO WEI ◽  
LINQIN YANG ◽  
XISHENG YANG ◽  
...  

The transport properties of magnetic-atoms doped Mn x Bi 2-x Se 3 single crystals are studied. The samples exhibit approximately similar temperature dependence of resistivity behavior under various applied magnetic fields from zero to 9 T. Magnetoresistance (MR) is modified significantly by high concentration of Mn dopants. The scatterings mechanism between the magnetic impurities and electrons plays an important role in both transport properties and MR effect.


2009 ◽  
Vol 11 (1) ◽  
pp. 013022 ◽  
Author(s):  
Sayani Majumdar ◽  
Himadri S Majumdar ◽  
Reino Laiho ◽  
Ronald Österbacka

1988 ◽  
Vol 102 ◽  
pp. 165-174
Author(s):  
C. de Michelis

AbstractImpurities being an important concern in tokamaks, spectroscopy plays a key role in their understanding. Techniques for the evaluation of concentrations, power losses and transport properties are surveyed, and a few developments are outlined.


Author(s):  
Alain Claverie ◽  
Zuzanna Liliental-Weber

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.


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