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arXiv · 1903.11819

Superconductivity at 48 K of heavily hydrogen-doped SmFeAsO epitaxial films grown by topotactic chemical reaction using CaH2

Jumpei Matsumoto·Kota Hanzawa·Masato Sasase·Silvia Haindl·Takayoshi Katase·Hidenori Hiramatsu·Hideo Hosono
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Abstract

High-critical-temperature (Tc) superconductivity at 48 K is reported for hydrogen-doped SmFeAsO epitaxial films on MgO single-crystal substrates. The key processes are pulsed laser deposition to grow undoped SmFeAsO epitaxial films and subsequent topotactic chemical reaction using CaH2 powders under evacuated silica-glass ampule atmosphere. Based on this post-deposition thermal annealing treatment that we have developed, a maximum hydrogen concentration x = ~0.35 was realized in SmFeAs(O1-xHx). Disordered hydrogen-substitution at O sites is experimentally confirmed directly by atomic-scale microstructural observations. Magnetization measurement validates the bulk nature of the high-Tc superconductivity in the films. This method will become an effective and general method to fabricate various high-quality oxyhydride epitaxial films.

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Jumpei Matsumoto, Kota Hanzawa, Masato Sasase, Silvia Haindl, Takayoshi Katase, Hidenori Hiramatsu, Hideo Hosono. 2019-03-28. Superconductivity at 48 K of heavily hydrogen-doped SmFeAsO epitaxial films grown by topotactic chemical reaction using CaH2. https://doi.org/10.1103/physrevmaterials.3.103401

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