Heterostructures of Bi-4334 and MgB₂ superconductors

We report the studies on hetero structures of Bi-4334 and MgB₂ superconductors. The two superconductors were arranged in the form of bulk multilayers using hydraulic pressure system. X-ray diffraction pattern and dc magnetization studies confirm the presence of both superconducting phases in this try-layer hetero structured sample. The d.c magnetization shows the superconducting onset at 77 K and 39 K for Bi-4334 and MgB₂ phases respectively. Critical current density (J_c) is calculated from hysteresis loop of the sample in both in-plane field and out of plane field configurations. Inverted anisotropy in J_c is observed due to enhancement of ab-plane properties because of multilayer growth process. Morphology of the samples at surface and interface of two superconducting layers is discussed in view of Field emission scanning electron microscopy.