Dresden 2003 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 20: Postersitzung IV (Mesoskopische Systeme, Supraleitung: Massivmaterialien, Bandleiter, Pinning, Vortexdynamik, Transporteigenschaften, Korngrenzen)
TT 20.47: Poster
Donnerstag, 27. März 2003, 14:30–19:00, P2c, P2d
Crystal Growth and Properties of HoNi2B2C — •Dmitri Souptel, Günter Behr, Wolfgang Löser, Günter Fuchs, and Konstantin Nenkov — Leibniz-Institute for Solid State and Materials Research Dresden, PF 27 01 16, D-01171 Dresden, Germany
High-quality HoNi2B2C single crystals 6 mm in diameter and 30 - 50 mm in length were grown by FZ technique with optical heating. The crystals are crack free, without inclusions of second phases and single-crystalline over the whole cross-section.
In contrast to single crystals grown by the Ni2B-flux method the melt grown HoNi2B2C crystals exhibit three different types of behaviour: superconducting transition at Tc about 8 K, coexistence of superconductivity and magnetic ordering at 5.5 K with re-entrant behaviour at T = 5.5 K and absence of superconductivity. Heat treatments of the single crystalline samples at moderate temperatures of 500 to 1000oC lead to an unexpected strong influence on the superconducting and magnetic properties. This suggests modifications in site occupancy of the light elements in the HoNi2B2C lattice.