Morphological control of cuprate superconductors using sea sponges as templates

Abstract

Functional porous superconducting sponges, consisting of YBa₂Cu₃O_6+δ (YBCO) and Bi₂Sr₂CaCu₂O_8+δ (BSCCO), were created by biotemplating with natural sea sponges. Naturally occurring calcium in the spongin fibers was utilized to dope YBCO and to form BSCCO without adding any external calcium source. The sample morphology was confirmed with scanning electron microscopy, and the sample composition was confirmed with energy-dispersive X-ray spectroscopy, powder electron diffraction and high-resolution transmission electron microscopy. The YBCO sponge exhibited a critical temperature (T_c) of approximately 70 K, and the BSCCO sponge showed a T_c of 77 K. This proof-of-concept study demonstrates the feasibility of using sea sponges as a greener, more sustainable template for superconductor synthesis.