Dresden 2026 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 17: Focus Session: High-Temperature Superconductivity in Hydride Materials at High Pressures (joint session TT/DS)
DS 17.2: Topical Talk
Donnerstag, 12. März 2026, 15:30–16:00, HSZ/0003
High-pressure synthesis of hydrides and their characterisation by single-crystal X-ray diffraction — •Natalia Dubrovinskaia1 and Leonid Dubrovinsky2 — 1Material Physics, University of Bayreuth; Bayreuth, Germany — 2Bayerisches Geoinstitut, University of Bayreuth, Germany
The sulfur-hydrogen, lanthanum-hydrogen, and yttrium-hydrogen systems have attracted significant interest following reports of near-ambient-temperature superconductivity in some of their high-pressure phases. Here, we present single-crystal X-ray diffraction studies of these systems, supported by density functional theory calculations, which reveal an unexpected chemical and structural diversity in S, La, and Y hydrides synthesised at 50*200 GPa. Syntheses were carried out in diamond anvil cells by laser heating S, La, LaH3, or Y together with hydrogen-rich precursors-ammonia borane or paraffin oil. The arrangements of heavy atoms in newly formed phases were determined from SCXRD data, while hydrogen contents were estimated using empirical relationships and ab initio calculations. Our study also uncovers the formation of previously unreported metal allotropes, carbides, and ternary compounds at high pressure. The complex phase diversity, variable hydrogen stoichiometries, and metallic nature of these high-pressure hydrides, as revealed by theory, highlight the challenges in identifying the superconducting phases and understanding electronic transitions in materials synthesised under extreme conditions.
Keywords: high pressure; hydrides; synthesis; crystal structure