Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 7: Superconductivity & Solids At Low Temperature - Poster Session
TT 7.41: Poster
Montag, 27. März 2006, 14:00–17:45, P1
Superconducting Proximity Effect in Co2MnGe/V/Co2MnGe Trilayers — •Dirk Sprungmann, Kurt Westerholt, and Hartmut Zabel — Institut für Experimentalphysik/Festkörperphysik,Ruhr-Universität Bochum, 44780 Bochum, Germany
We have studied the superconducting proximity
effect in the trilayer system Co2MnGe/V/Co2MnGe. The motivation of
this work was, whether the exchange field of the ferromagnetic
Heusler alloy affects the critical temperature Tc in the same
way as simple elementary ferromagnets do. For this purpose we
measured the critical temperature Tc at different thicknesses
of the V and the Co2MnGe layers and determined the critical
fields Hc∥ (T) and Hc⊥ (T) as a function of
temperature. We applied the theory of Z. Radovic et al. and L.R.
Tagirov to the data and obtained the coherence lengths of the pair
wave function in the superconducting Vanadium ξs and in the
ferromagnetic Heusler compound ξF. Additionally the
theoretical fits provide the characteristic transparency
parameters of the V/Co2MnGe interface. The comparison of the
experimental results and the theory reveals quantitative
agreements with the classical proximity effect. However,
quantitatively we also find inconsistencies in the parameters we
have derived. This is due to the spin glass type of magnetic order
for small thicknesses of the Co2MnGe-phase, which is a complication
compared to the classical proximity effect.
We
acknowledge financial support through SFB 491.