Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 18: Superconductivity: Fabrication and Characterization
TT 18.6: Vortrag
Dienstag, 24. März 2009, 15:30–15:45, HSZ 105
Magnetic measurements under pressure of the non-centrosymmetric superconductor Li2Pd3B synthesized by a semi-open method — •P. Badica1,2, G. Jakob1, A. Beleanu1, V. Ksenofontov1, and C. Felser1 — 1Mainz University, Mainz, Germany — 2National Institute of Materials Physics, Bucharest, Romania
Samples of the non-centrosymmetric superconductor Li2Pd3B were synthesized from mixtures of the elements. A simple semiopen method is proposed using endings-pressed stainless steel tubes placed in a vacuum furnace. Heating regime employed a short-time overheating at 900 ∘ C and a slow cooling step between 720 to 550 ∘ C with a constant cooling rate of 1 ∘ C/min. Extra amount of Li was necessary to compensate losses and the optimum starting composition was Li2.4Pd3B. Superconducting properties, such as lower and upper critical fields and critical temperature Tc, were measured by magnetic measurements (MPMS magnetometer) under hydrostatic pressures up to 2 GPa (using a self-made pressure capsule). Superconducting properties are decreasing with pressure. For example, under normal pressure samples show a critical temperature of 8-8.2 K and a sharp superconducting transition, while the results indicate for the decrease rate dTc/dP a value of 0.12 K/GPa. This value is about 3 times lower than the reported value measured by transport measurements on arc-melted samples.