Synthesis, Structure, and Properties of Clathrate Si30.3(8) P15.7(8) Se7.930(3)

Hui Zhang; Wei Peng; Gang Mu; Tao Hu; Fuqiang Huang; Xiaoming Xie

doi:10.1002/chem.201700972

Synthesis, Structure, and Properties of Clathrate Si_30.3(8) P_15.7(8) Se_7.930(3)

Chemistry. 2017 Jul 18;23(40):9505-9516. doi: 10.1002/chem.201700972. Epub 2017 May 19.

Authors

Hui Zhang^{1

2}, Wei Peng^{1

2}, Gang Mu^{1

2}, Tao Hu^{1

2}, Fuqiang Huang^{2

3}, Xiaoming Xie^{1

2}

Affiliations

¹ Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China.
² CAS Center for Excellence in Superconducting Electronics, Shanghai, 200050, P.R. China.
³ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics Institution, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai, 200050, P.R. China.

PMID: 28378371
DOI: 10.1002/chem.201700972

Abstract

The new clathrate single crystal Si_30.3(8) P_15.7(8) Se_7.930(3) was synthesized through a solid-state reaction, and it was characterized to have a unit cell parameter a=19.7614(1) Å and belong to space group Fm3‾ . In this clathrate structure, a Se1-Si3 bond forms in place of the tetrakaidecahedron structure, and pental dodecahedral cages composed of Si and P atoms encapsulate Se2, Se3, and Se4 guest atoms. Similar structures are observed in partial Te- and Ge-substituted compounds. Theoretical calculations based on an ordered formula Si₃₂ P₁₄ Se₇ showed a semiconducting electronic structure with a band gap of 0.711 eV. A photoelectric response was observed in this compound at room temperature. Across the whole temperature range, this material exhibited a weak temperature-dependent diamagnetic signal, and no phase transition or thermal anomaly was observed in heat capacity measurements.

Keywords: clathrates; crystal structure; electronic structure; magnetic properties; semiconductors.