Superconducting H5S2 phase in sulfur-hydrogen system under high-pressure

作者：Ishikawa Takahiro; Nakanishi Akitaka; Shimizu Katsuya; Katayama Yoshida Hiroshi; Oda Tatsuki; Suzuki Naoshi

来源：Scientific Reports, 2016, 6(1): 23160.

DOI：10.1038/srep23160

Recently, hydrogen sulfide was experimentally found to show the high superconducting critical temperature (T-c) under high-pressure. The superconducting T-c shows 30-70 K in pressure range of 100-170 GPa (low-T-c phase) and increases to 203 K, which sets a record for the highest T-c in all materials, for the samples annealed by heating it to room temperature at pressures above 150 GPa (high-T-c phase). Here we present a solid H5S2 phase predicted as the low-T-c phase by the application of the genetic algorithm technique for crystal structure searching and first-principles calculations to sulfur-hydrogen system under high-pressure. The H5S2 phase is thermodynamically stabilized at 110 GPa, in which asymmetric hydrogen bonds are formed between H2S and H3S molecules. Calculated T-c values show 50-70 K in pressure range of 100-150 GPa within the harmonic approximation, which can reproduce the experimentally observed low-T-c phase. These findings give a new aspect of the excellent superconductivity in compressed sulfur-hydrogen system.

• 出版日期2016-3-17