Magnetic Moment Peculiarities in Bismuth Bicrystals with Large Crystallite Disorientation Angles

TL;DR

This study reveals unique magnetic behaviors and the emergence of superconducting phases in large-angle bismuth bicrystals, highlighting the influence of crystallite interface structure on their properties.

Contribution

It demonstrates the existence of superconducting phases localized at the crystallite interface in bismuth bicrystals with large disorientation angles, a novel finding for this material.

Findings

Two superconducting phases observed at the interface

Superconducting phase with Tc ~ 8.4 K localized at the interface

Significant proximity effect in adjacent layers of the interface

Abstract

Magnetization measurements prove that the magnetic properties of large-angle (theta > 30o) bismuth bicrystals with crystallite interface (CI) of twisting type essentially differ from well-known results on single-crystalline specimens. Two superconducting phases were observed at CI of bicrystals (ordinary rhombohedral Bi is not a superconductor). It was shown that one of them (phase with Tc ~ 8,4 K) is localized in central part of crystallite interface. It was also found that in adjacent layers (width of layer d2 ~ 20 nm) of CI the proximity effect is significant.