Microstructure Evolution Mechanism and Mechanical Properties of Mg-RE Alloy at a Critical Transition Temperature of Material Performance

2020 ◽  
Vol 29 (11) ◽  
pp. 7198-7206
Author(s):  
Jianli He ◽  
Jun Jiang ◽  
Fei Chen ◽  
Minglin Shi ◽  
Bo Wang ◽  
...  
2008 ◽  
Vol 63 (11-12) ◽  
pp. 1372-1375 ◽  
Author(s):  
H.P. Roeser ◽  
F. Hetfleisch ◽  
F.M. Huber ◽  
M.F. von Schoenermark ◽  
M. Stepper ◽  
...  

1988 ◽  
Vol 02 (05) ◽  
pp. 1101-1105 ◽  
Author(s):  
Miklos GULACSI ◽  
Zsolt GULACSI

The original Cooper pairing theory is reformulated for electrons confined in a layer. This analysis is motivated by the quasi-two-dimensional character of the oxidic superconductors, in case of which the extension of the initial (3D) Cooper framework is practically impossible. By considering the electrons moving in a flat box, due to quantum size effect the properties of these oxidic superconductors can be explained in a natural way. In this short communication we will concentrate to the variation of the critical transition temperature due to the layer thickness and to the number of conduction (Cu-O) planes. The results are confirmed by the experiment. This being an evidence for the presence of the charge confinement effect in the oxidic superconductors.


2008 ◽  
Vol 62 (12) ◽  
pp. 733-736 ◽  
Author(s):  
H.P. Roeser ◽  
F. Hetfleisch ◽  
F.M. Huber ◽  
M.F. von Schoenermark ◽  
M. Stepper ◽  
...  

2020 ◽  
Vol 842 ◽  
pp. 155874
Author(s):  
Yuanhang Chen ◽  
Chunli Yang ◽  
Chenglei Fan ◽  
Yimin Zhuo ◽  
Sanbao Lin ◽  
...  

2011 ◽  
Vol 319-320 ◽  
pp. 161-166 ◽  
Author(s):  
Morsy M.A. Sekkina ◽  
M. El-Hofy ◽  
Khaled M. Elsabawy ◽  
M. Bediwy

BSCCO 2212 superconducting samples, doped Tellurium, with the chemical formula Bi2-xTexSr2CaCu2O8, were prepared by the conventional solid state reaction technique. The prepared samples were studied utilizing XRD, DC-electrical conductivity and SEM. XRD spectra indicated that 2212 with tetragonal structure is the major phase, whereas Bi-2201 and CaTeO4 are minor phases. At higher Te-additions x, traces from some other semi conducting phases were detected. The critical transition temperature Tcoffset was found to decrease non-linearly with x, which attributed to the hole filling caused by the liberated electrons of Te4+ ions. For x–values in the range 0.1 ≤ x ≤ 0.4, the steepness of (ρ vs T) relationship increases abruptly around 150 K; this was attributed to change in the oxygen vacancy feature (phase-like transition). SEM photographs revealed that as Te-content increases the compactness of the surface and the connectivity of the grains decreases, while pores and voids increase as a result of decreasing the amount of Bi and presence of multiple-phases in the sample.


2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Gang Mu ◽  
Bo Gao ◽  
Xiaoming Xie ◽  
Yoichi Tanabe ◽  
Jingtao Xu ◽  
...  

Low-temperature specific heat (SH) is measured on the postannealed Ba(Fe1−xNix)2As2single crystal withx= 0.058 under different magnetic fields. The sample locates on the overdoped sides and the critical transition temperatureTcis determined to be 14.8 K by both the magnetization and SH measurements. A simple and reliable analysis shows that, besides the phonon and normal electronic contributions, a clearT2term emerges in the low temperature SH data. Our observation is similar to that observed in the Co-doped system in our previous work and is consistent with the theoretical prediction for a superconductor with line nodes in the energy gap.


2005 ◽  
Vol 19 (16) ◽  
pp. 771-778 ◽  
Author(s):  
R. B. SAXENA ◽  
RAJIV GIRI ◽  
V. P. S. AWANA ◽  
H. K. SINGH ◽  
M. A. ANSARI ◽  
...  

Samples of series Bi 1.6 Pb 0.4 Sr 2 Ca 2 Cu 3-x Zn x O 10-δ with x = 0.0, 0.015, 0.03, 0.06, 0.09 and 0.12 are synthesized by solid-state reaction route. All the samples crystallize in tetragonal structure with majority (> 90%) of Bi -2223( Bi 2 Sr 2 Ca 2 Cu 3 O 10) phase (c-lattice parameter ~ 36 Å). The proportion of Bi -2223 phase decreases slightly with an increase in x. The lattice parameters a and c of main phase ( Bi -2223) do not change significantly with increasing x. Superconducting critical transition temperature (Tc) decreases with x as evidenced by both resistivity [ρ(T)] and ac magnetic susceptibility [χ(T)] measurements. Interestingly the decrement of Tc is not monotonic and the same saturates at around 96 K for x > 0.06. In fact Tc decreases fast (~ 10 K/at%) for x = 0.015 and 0.03 samples and later nearly saturates for higher x values. Present results of Zn doping in Bi -2223 system are compared with other Zn -doped HTSC (high temperature superconducting) systems, namely the RE -123 ( REBa 2 Cu 3 O 7) and La -214 (( La, Sr )2 CuO 4).


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