Reentrant superconductivity in HoNi5-NbN-HoNi5 nanostructures
1 Condensed Matter - Low Dimensional Systems Laboratory, Department of Physics, Indian Institute of Technology Kanpur - Kanpur - 208016, India
2 CSIR - National Physical Laboratory - New Delhi - 110012, India
Received: 8 May 2013
Accepted: 25 August 2013
Superconductivity (S) and ferromagnetism (F) are probed through transport and magnetization measurements in nanometer scale HoNi5-NbN (F-S) bilayers and HoNi5-NbN-HoNi5 (F-S-F) trilayers. The choice of materials has been made on the basis of their comparable ordering temperatures and strong magnetic anisotropy in HoNi5. We observe the normal state reentrant behavior in resistance vs. temperature plots of the F-S-F structures just below the superconducting transition in the limited range of HoNi5 layer thickness dHN () when is fixed at. The reentrance is quenched by increasing the out-of-plane () magnetic field and transport current where as in-plane () field of has no effect on the reentrance. The origin of the reentrant behavior seen here in the range is attributed to a delicate balance between the magnetic exchange energy and the condensation energy in the interfacial regions of the trilayer.
PACS: 74.45.+c – Proximity effects; Andreev reflection; SN and SNS junctions / 74.62.-c – Transition temperature variations, phase diagrams / 74.78.-w – Superconducting films and low-dimensional structures
© EPLA, 2013