Development of Boron‐Doped Diamond Electrodes in Diamond Anvil Cell and Application for Exploration of Superconducting Hydrides

ABSTRACT One of the grand challenges in physics is the exploration of room‐temperature superconductivity and the promising candidate is hydrides under high‐pressure. In this review, we introduce a custom‐designed diamond anvil cell equipped with boron‐doped diamond electrodes that enables both the synthesis and in situ evaluation of superconductivity under extreme conditions without complex experimental configurations. The metallic boron‐doped diamond epitaxial film is selectively grown on the diamond anvil surface by microwave‐assisted plasma chemical vapor deposition, combined with lithographic patterning techniques. We describe the fabrication process of the boron‐doped diamond electrodes and demonstrate their application to the synthesis and transport measurements of superconducting hydrides. This approach provides a powerful and reusable platform for exploring new superconductors at ultrahigh pressures.