Structural Origin of the Semiconducting Properties of Sb4Mo20O62

✍ Scribed by Enric Canadell; Michel Evain; Marcel Ganne; Myung-Hwan Whangbo

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 330 KB
• Volume: 105
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1993.1236

✦ Synopsis

The origin of the semiconducting properties of the molybdenum bronze (\mathrm{Sb}{4} \mathrm{Mo}{20} \mathrm{O}{62}) was examined by performing tight-binding electronic band structure calculations. Our calculations show a band gap at the Fermi level, so that (\mathrm{Sb}{4} \mathrm{Mo}{20} \mathrm{O}{62}) is not a Mott insulator but a regular semiconductor. Analysis of the low-lying (t_{28})-block bands reveals that the band gap originates from the (\mathrm{O}-\mathrm{Mo} \cdots \mathrm{O}) alternations in the six different types of (\mathrm{MoO}{6}) octahedra present in (\mathrm{Sb}{4} \mathrm{Mo}{20} \mathrm{O}{62}), and the conductivity of this bronze is one-limensional despite its three-dimensional crystal structure. The conducting properties of other (M_{4} M_{11}^{\prime} \mathrm{O}_{12}\left(M=\mathrm{Sb}, 13 ; M^{\prime}=\mathrm{Mo}\right.). W) phases are also discussed. Of 1993 Academic Press, Inc.