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Full-Text Articles in Engineering
Superconductivity Induced By Phosphorus Doping And Its Coexistence With Ferromagnetism In Eufe2(As0.7p0.3)2, Zhi Ren, Qian Tao, Shuai Jiang, Chunmu Feng, Cao Wang, Jianhui Dai, Guanghan Cao, Zhu-An Xu
Superconductivity Induced By Phosphorus Doping And Its Coexistence With Ferromagnetism In Eufe2(As0.7p0.3)2, Zhi Ren, Qian Tao, Shuai Jiang, Chunmu Feng, Cao Wang, Jianhui Dai, Guanghan Cao, Zhu-An Xu
Faculty of Engineering - Papers (Archive)
We have studied EuFe$_{2}$(As$_{0.7}$P$_{0.3}$)$_{2}$ by the measurements of x-ray diffraction, electrical resistivity, thermopower, magnetic susceptibility, magnetoresistance and specific heat. Partial substitution of As with P results in the shrinkage of lattice, which generates chemical pressure to the system. It is found that EuFe$_{2}$(As$_{0.7}$P$_{0.3}$)$_{2}$ undergoes a superconducting transition at 26 K, followed by ferromagnetic ordering of Eu$^{2+}$ moments at 20 K. This finding is the first observation of superconductivity stabilized by internal chemical pressure, and supplies a rare example showing coexistence of superconductivity and ferromagnetism in the ferro-arsenide family.
Stress/Strain Induced Flux Pinning In Highly Dense Mgb2 Bulks, Rong Zeng, S X. Dou, Lin Lu, Wenxian Li, Chung-Kiak Poh, Jung Ho Kim, Josip Horvat, Dongqi Shi, Jianli Wang, Paul G. Munroe, X. F. Wang, Rongkun Zheng, S. P. Ringer, M Rindfleisch, Mike Tomsic
Stress/Strain Induced Flux Pinning In Highly Dense Mgb2 Bulks, Rong Zeng, S X. Dou, Lin Lu, Wenxian Li, Chung-Kiak Poh, Jung Ho Kim, Josip Horvat, Dongqi Shi, Jianli Wang, Paul G. Munroe, X. F. Wang, Rongkun Zheng, S. P. Ringer, M Rindfleisch, Mike Tomsic
Faculty of Engineering - Papers (Archive)
We have systematically studied the flux pinning behavior of MgB2 bulks synthesized by direct diffusion of Mg into pressed pellets of high purity crystalline B powder, with and without mixing with C and SiC nanoparticles, at a reaction temperature of 850degC for 10 hrs. All of the samples showed very high purity and high density, but their microstructure and flux pinning behavior showed significant differences. It was found that the pure MgB2 agrees with the deltaTc pinning model, nano-C doped MgB2 agrees with the deltal pinning model, while the SiC+MgB2 composite agrees …
Stretching Induced Hall Current And Conductance Anisotropy In Graphene, A R Wright, Chao Zhang
Stretching Induced Hall Current And Conductance Anisotropy In Graphene, A R Wright, Chao Zhang
Faculty of Engineering - Papers (Archive)
We evaluate the effect of stretching on the optical conductance of a single layer graphene sheet. It is found that the low energy (Dirac regime) isotropy that leads to the `universal conductance' is lost. More significantly, due to the loss of C_3 symmetry, a non-zero Hall conductance emerges for stretching along chiral directions, reaching a maximum at a stretching angle of 45 degrees, and being as high a S_0 = e2/4h at van Hove singular point for bond angle changes of about 2 degrees.
Thermal-Strain-Induced Enhancement Of Electromagnetic Properties Of Sic-Mgb2 Composites, Rong Zeng, S X. Dou, Lin Lu, Wenxian Li, Jung Ho Kim, Paul G. Munroe, Rongkun Zheng, S P. Ringer
Thermal-Strain-Induced Enhancement Of Electromagnetic Properties Of Sic-Mgb2 Composites, Rong Zeng, S X. Dou, Lin Lu, Wenxian Li, Jung Ho Kim, Paul G. Munroe, Rongkun Zheng, S P. Ringer
Faculty of Engineering - Papers (Archive)
The effect of thermal strain caused by the different thermal expansion coefficients (α) of the MgB2 and SiC phases on the electromagnetic properties was studied for SiC–MgB2 composite, which was made by premixing SiC and B, followed by Mg diffusion and reaction. Thermal strain in the MgB2 phase was demonstrated with x-ray diffraction, Raman spectroscopy, and transmission electron microscopy. In contrast to the common practice of improving the critical current density Jc and the upper critical field Hc2 of MgB2 through chemical substitution, by taking advantage of residual thermal strains, we …
Flux Pinning Of Stress Induced Magnetic Inhomogeneity In The Bilayers Of Yba2cu3o7-Δ/La0.67sr0.33mno3-Δ, S X. Dou, Rong Zeng, Y M. Lu, L Peng, B Gao, Z Y. Liu, F Fan, C B. Cai, C Z. Chen
Flux Pinning Of Stress Induced Magnetic Inhomogeneity In The Bilayers Of Yba2cu3o7-Δ/La0.67sr0.33mno3-Δ, S X. Dou, Rong Zeng, Y M. Lu, L Peng, B Gao, Z Y. Liu, F Fan, C B. Cai, C Z. Chen
Faculty of Engineering - Papers (Archive)
Elaborately designed bilayers consisting of epitaxial YBa2Cu3O7-δ (YBCO) and La0.67Sr0.33MnO3-δ (LSMO) films were fabricated by pulsed laser deposition with respect to the investigation into magnetic-dependent vortex pinning effect. The improvement in the critical current density and a pronounced upward shift in the superconducting irreversibility line based on magnetotransport measurements are observed when compared to the pure YBCO film, suggesting the enhancement in flux pinning in the studied bilayer. It is believed that the improved flux pinning for YBCO arises from the magnetic inhomogeneity of the underlying LSMO. Magnetization measurements show …