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Superconducting phase diagram of single crystal MgB{sub 2}.

Description: Using magnetization, transport and single-crystal specific heat measurements we have determined the superconducting phase diagram of MgB{sub 2}. A zero-temperature in-pane coherence length of 9.4 nm is found. The superconducting anisotropy changes monotonously from a value around 2 near T{sub c} to above 4.5 near 22 K. We present strong evidence for a surface superconducting state for H{parallel}c which might account for the wide spread in reported values of the superconducting anisotropy.
Date: September 17, 2002
Creator: Welp, U.; Rydh, A.; Karapetrov, G.; Kwok, W. K.; Crabtree, G. W.; Marcenat, C. et al.
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Partner: UNT Libraries Government Documents Department
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Momentum-dependent scanning tunneling spectroscopy in MgB{sub 2}.

Description: We present study of the anisotropic superconductor MgB{sub 2} using a combination of scanning tunneling microscopy and spectroscopy. The results reveal two distinct energy gaps at {Delta}{sub 1} = 2.3 meV and {Delta}{sub 2} = 7.1 meV. Different spectral weights of the partial superconducting density of states are a reflection of different tunneling directions in this multi-band system. Our experimental observations are consistent with the existence of two-band superconductivity in the presence … more
Date: July 31, 2002
Creator: Karapetrov, G.; Iavarone, M.; Koshelev, A. E.; Kwok, W. K.; Crabtree, G. W.; Hinks, D. G. et al.
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Partner: UNT Libraries Government Documents Department
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Phase diagram of single crystal MgB{sub 2}.

Description: Using magnetization, magneto-transport and single-crystal specific heat measurements the authors have determined the superconducting phase diagram of MgB{sub 2}. The superconducting anisotropy {gamma} changes monotonously from a value of around 2 near T{sub c} to above 4.5 at 22 K. For H{parallel}c a pronounced peak effect in the critical current occurs at the upper critical field. They present a strong evidence for a surface superconducting state for H{parallel}c which might account for the wi… more
Date: September 30, 2002
Creator: Karapetrov, G.; Welp, U.; Rydh, A.; Iavarone, M.; Kwok, W. K.; Crabtree, G. W. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The influence of structural defects on intragranular critical currents of bulk MgB[sub 2].

Description: Bulk MgB2 samples were prepared under different synthesis conditions and analyzed by scanning and transmission electron microscopy. The critical current densities were determined from the magnetization versus magnetic field curves of bulk and powder-dispersed-in-epoxy samples. Results show that through a slow cooling process, the oxygen dissolved in bulk MgB2 at high synthesis temperatures can segregate and form nanometer-sized coherent precipitates of Mg(B,O)2 in the MgB2 matrix. Magnetization… more
Date: January 1, 2002
Creator: Serquis, A. (Adriana); Liao, Xiaozhou; Civale, L. (Leonardo); Zhu, Y. T. (Yuntian Theodore); Coulter, J. Y. (James Y.); Peterson, D. E. (Dean E.) et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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MICROSTRUCTURE OF SUPERCONDUCTING MGB(2).

Description: Recently, Akimitsu and co-workers [1] discovered superconductivity at 39 K in the intermetallic compound MgB{sub 2}. This discovery provides a new perspective on the mechanism for superconductivity. More specifically, it opens up possibilities for investigation of structure/properties in a new class of materials. With the exceptions of the cuprate and C{sub 60} families of compounds, MgB{sub 2} possesses the highest superconducting transition temperature T{sub c}. Its superconductivity appears … more
Date: July 12, 2001
Creator: Zhu, Y.; Li, Q.; Wu, L.; Volkov, V.; Gu, G. & Moodenbaugh, A. R.
Item Type: Refine your search to only Book
Partner: UNT Libraries Government Documents Department
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Phase Equilibria Relationships of High-Tc Superconductors

Description: As an integral part of a R&D program partially supported by the Electricity Delivery and Energy Reliability Office of DOE, we have determined phase equilibria data and phase diagrams for the three generations of superconductor materials: 1st generation, (Bi,Pb)-Sr-Ca- Cu-O systems; 2nd generation, Ba-R-Cu-O systems (R=lanthanides and yttrium); and 3rd generation, MgB2 systems. Our studies involved bulk materials, single crystals and thin films. This report gives a summary of our accomplishments… more
Date: January 11, 2011
Creator: Wong-Ng, Winnie
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Density Functional Theory Simulations Predict New Materials for Magnesium-Ion Batteries (Fact Sheet), NREL Highlights, Science

Description: Multivalence is identified in the light element, B, through structure morphology. Boron sheets exhibit highly versatile valence, and the layered boron materials may hold the promise of a high-energy-density magnesium-ion battery. Practically, boron is superior to previously known multivalence materials, especially transition metal compounds, which are heavy, expensive, and often not benign. Based on density functional theory simulations, researchers at the National Renewable Energy Laboratory (… more
Date: October 1, 2011
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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