笼内相互作用在 SrSi 的包合物超导体中

Chemische Metallkunde, Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187, Dresden, Germany.

Chemistry. 2020 Jan 16;26(4):830-838. doi: 10.1002/chem.201904170. Epub 2019 Dec 12.

The clathrate I superconductor Sr Si is obtained under high-pressure high-temperature conditions, at 5 GPa and temperatures in the range of 1273 to 1373 K. At ambient pressure, the compound decomposes upon heating at T=796(5) K into Si and SrSi . The crystal structure of the clathrate is isotypic to that of Na Si . Chemical bonding analysis reveals conventional covalent bonding within the silicon network as well as additional multi-atomic interactions between Sr and Si within the framework cages. Physical measurements indicate a bulk BCS type II superconducting state below T =3.8(3) K.

高压高温条件下可获得笼型 I 超导体 SrSi，压力为 5 GPa，温度在 1273 到 1373 K 之间。常压下，该化合物在 796(5) K 加热时分解为 Si 和 SrSi。笼型化合物的晶体结构与 NaSi 同型。化学键分析表明，硅网络中存在传统的共价键，而在框架笼中 Sr 和 Si 之间存在额外的多原子相互作用。物理测量表明，在 T =3.8(3) K 以下存在体 BCS 型 II 超导态。