Proximity effect induced by Kondo interaction in a network composed of YBCO and spin density wave

• Proximity effect in YBCO and YMnO3 is controlled by Kondo interaction.
• Nonlinear I–VI–V nature is observed in YBCO below TcTc.
• Absence of Kosterlitz–Thouless transition in YBCO with VRH in normal state.
• Diluted YMnO3 affects I–VI–V drastically in same set of temperatures.
• Coherence length suggested by de Gennes is affected by Kondo interaction.

The possibility of the proximity effect mediated by Kondo interaction in YBCO embedded in system of diluted magnetic spin ordering has been studied. An YBCO sample is selected in which both metal to insulator transition and superconducting state exist in the different ranges of temperature. The intergranular network of the bulk Y-123 has been modified by the inclusion of YMnO3 which has a well defined magnetic structure depending on temperature. The current–voltage measurements have been carried out in pure Y-123 at several temperatures. At the same set of temperatures the current–voltage curves in presence of YMnO3 have been studied. The role of the diluted spin magnetic ordering in tuning proximity effect and conduction property in binary systems is associated with reduced coherence length in the normal region.