We investigated the superconducting properties of V/Cr multilayers with the different preferred orientations of (100) and (110). These samples were grown epitaxially on MgO (100) and Al2O3 (1120) single-crystal substrates. The Cr layer thickness was varied from dcr=2 to 140Å at a constant V layer thickness of 300 Å. In (100) V/Cr, the critical temperature Tc abruptly drops with increasing dCr from 5 to 40 Å and shows a plateau above 40 Å. In (110) V/Cr, Tc gradually decreases up to dCr=80 Å and keeps a higher value than in (100). For the temperature dependence of parallel upper critical fields, Hc2∥(T), the 3D-to-2D dimensional crossover phenomenon takes place in dCr=10∼25 Å for (100) V/Cr and 10∼70 Å for (110) V/Cr. 2D behavior of Hc2∥(T), which implies the decoupling of superconducting V layers by the Cr layer, is achieved in the range of dCr above 40 Å for (100) and 80 Å for (110). The ratio of Hc2⊥ to Hc2⊥ for (100) V/Cr is enhanced in comparison with that for (110). Our results indicate that the strong pair-breaking effect operates at the interfaces of (100) V/Cr.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering