High pressure studies of T[sub c] and lattice parameters of MgB[sub 2]

Schlachter, Sonja I.; Fietz, Walter H.; Grube, Kai; Goldacker, Wilfried
May 2002
AIP Conference Proceedings;2002, Vol. 614 Issue 1, p809
Academic Journal
We performed ac-susceptibility measurements of magnesium diboride powder samples under pure hydrostatic pressures up to 0.4 GPa and under quasi-hydrostatic pressure conditions up to 8 GPa in a helium gas pressure cell and a diamond-anvil cell (DAC), respectively. Furthermore, the DAC has been used to investigate the lattice compression by X-ray diffraction. Under helium gas pressure the superconducting transition temperature shows a linear decrease dT[sub c]/dp = -1.13 K/GPa. The pressure effect is fully reversible with a return to the initial T[sub c] of 37.5 K after pressure release. In the diamond-anvil cell the application of pressure leads to a stronger T[sub c]-decrease than in the helium gas pressure cell, and after the release of pressure a degradation effect with lower T[sub c] and a broader transition compared to the first measurement at ambient pressure occurs. Such degradation may be explained by shear stresses and uniaxial pressure components, which cannot be avoided in a DAC at low temperatures. Considering the anisotropic AlB[sub 2]-type structure with alternating honeycomb boron and magnesium layers, MgB[sub 2] seems to be very sensitive to such non-hydrostatic pressure components, which would explain the spread of dT[sub c]/dp values reported in the literature.


Related Articles

  • Low-temperature high-pressure preparation of transparent nanocrystalline MgAl2O4 ceramics. Lu, T. C.; Chang, X. H.; Qi, J. Q.; Luo, X. J.; Wei, Q. M.; Zhu, S.; Sun, K.; Lian, J.; Wang, L. M. // Applied Physics Letters;5/22/2006, Vol. 88 Issue 21, p213120 

    Transparent MgAl2O4 spinel nanoceramics have been sintered at relatively low-temperature (500–700 °C) under high pressure (2–5 GPa) using a hydrostatic press with high-temperature-calcined nanopowders. The morphology, nanostructure, optical property, and density of ceramics were...

  • Thermoelastic properties of minerals at high temperature. UPADHYAY, SANJAY; CHANDRA, HEM; JOSHI, MEENAKASHI; JOSHI, DEEPIKA // Pramana: Journal of Physics;Jan2011, Vol. 76 Issue 1, p183 

    The knowledge of elasticity of the minerals is useful for interpreting the structure and composition of the lower mantle and also in seismic studies. The purpose of the present study is to discuss a simple and straightforward method for evaluating thermoelastic properties of minerals at high...

  • Technical aspects of cold high pressure densification (CHPD) on long lengths of In Situ MgB2 wires with enhanced Jc values. Flükiger, R. L.; Hossain, M. S. A.; Kulich, M.; Senatore, C. // AIP Conference Proceedings;6/12/2012, Vol. 1435 Issue 1, p353 

    The technical aspects correlated with the observed enhancement of mass density and critical current density in the filaments of in situ MgB2 wires by means of the recently developed Cold High Pressure Densification (CHPD) are reviewed. The present analysis first summarizes the results obtained...

  • Formation of MgO whiskers on the surface of bulk MgB2 superconductors during in situ sintering. Qingzhi Shi; Yongchang Liu; Zhiming Gao; Qian Zhao // Journal of Materials Science;Feb2008, Vol. 43 Issue 4, p1438 

    Magnesium oxide (MgO) whiskers (with diameters of about 60–80 nm) formed on the surface of bulk polycrystalline MgB2 superconductor at a relative low temperature (720 °C) during in situ sintering process. The reaction between Mg and B powders begins at a temperature below melting point...

  • Pressure Induced Structural and Magnetic Phase transition in Magnesium Nitrides MgNx (x = 1, 2, 3):A First Principles Study. Rajeswarapalanichamy, R.; Sudhapriyanga, G.; Cinthia, A. Jemmy; Santhosh, M.; Murugan, A. // AIP Conference Proceedings;2014, Vol. 1591, p53 

    The structural and magnetic properties of magnesium nitrides are investigated by the first principles calculations based on density functional theory using Vienna ab-initio simulation package. The calculated lattice parameters are in good agreement with the available results. A pressure-induced...

  • Hopping Conductivity of Carbynes Modified under High Pressures and Temperatures: Galvanomagnetic and Thermoelectric Properties. Demishev, S. V.; Pronin, A. A.; Glushkov, V. V.; Sluchanko, N. E.; Samarin, N. A.; Kondrin, M. V.; Lyapin, A. G.; Brazhkin, V. V.; Varfolomeeva, T. D.; Popova, S. V. // Journal of Experimental & Theoretical Physics;Jul2002, Vol. 95 Issue 1, p123 

    The conductivity, thermopower, and magnetoresistance of carbynes structurally modified by heating under a high pressure are investigated in the temperature range 1.8-300 K in a magnetic field up to 70 kOe. It is shown that an increase in the synthesis temperature under pressure leads to a...

  • SPECIFYING AND INSTALLING HIGH-PRESSURE FOG SYSTEMS. Robb, Drew // Power Engineering;Apr2000, Vol. 104 Issue 4, p48 

    Focuses on how to specify and install a high-pressure fog system. Benefits of a fog system; Quality of fog systems; Installation positions of fog system in the turbine inlet air system.

  • Importance of two-dimensional effects for the generation of ultra high pressures obtained in laser colliding foil experiments. Faral, B.; Fabbro, R.; Virmont, J.; Cottet, F.; Romain, J. P.; Pépin, H. // Physics of Fluids B: Plasma Physics;Feb90, Vol. 2 Issue 2, p371 

    A 12 μm polyester foil is accelerated by a 0.26 μm wavelength laser and collides with a 15 μm thick molybdenum foil. The accelerating pressure is 45 Mbar (laser intensity≊3– 4×1014 W/cm2) and gives to the polyester foil a velocity of about 160 km/sec. The measurement of...

  • Product Comparison.  // Consulting-Specifying Engineer;Nov2003, Vol. 34 Issue 5, p67 

    Compares a number of heating boilers. Application of Scotch Marine heating boilers; Capacity of Cast Iron heating boilers; Advantages and disadvantages of Flexible Water Tube heating boilers.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics