Tunneling current in magnetic-ferroelectric-superconducting heterostructures

We report the tunneling current behavior of magnetic-ferroelectric-superconducting heterostructures for multistates non-volatile random access memory (NVRAM) elements. A heterostructure of La0.67 Sr0.33 MnO3 (LSMO) (50 nm)/PbZr0.52 Ti0.48 O3 (PZT) (5 nm)/Bi-Sr-Ca-Cu2 -OX (BSCCO) (100 nm)/LaAlO3 (LAO) architecture was fabricated by pulsed laser deposition technique. The tunneling effects were investigated well above and below the superconducting phase transition temperature of the BSCCO bottom electrode. A divergent current and conductance paths were observed for polarization up and down direction above the coercive field of the ferroelectric tunnel barrier. This behaviour was significant below T s where the moderate effect of the external magnetic field was also observed on the tunneling current. The dynamic conductance G (V ) data fitted well with Brinkman's model for both polarizations up and polarization down states which suggest the presence of large tunnel electro-resistance.