A metal-insulator transition in R2O2Bi with an unusual Bi2- square net (R = rare earth or Y)

Hiroshi Mizoguchi; Hideo Hosono

doi:10.1021/ja111015p

A metal-insulator transition in R2O2Bi with an unusual Bi2- square net (R = rare earth or Y)

J Am Chem Soc. 2011 Mar 2;133(8):2394-7. doi: 10.1021/ja111015p. Epub 2011 Feb 8.

Authors

Hiroshi Mizoguchi¹, Hideo Hosono

Affiliation

¹ Frontier Research Center, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan.

PMID: 21302922
DOI: 10.1021/ja111015p

Abstract

A series of tetragonal ThCr(2)Si(2)-type compounds, R(2)O(2)Bi (R = rare earth or Y), are synthesized in which an unusual Bi(2-) anion forms a square net layer that is sandwiched between (R(2)O(2))(2+) fluorite layers. Two-dimensional (2D) electronic bands around the Fermi energy are predominantly composed of 6p(x)6p(y) orbitals in the Bi(2-) square net, which contains a positive hole per Bi(2-) ion. The decrease in the size of the square net caused by reducing the size of the R ion enhances the electrical conductivity because of the hole, resulting in a "chemical pressure"-induced metal-insulator transition.