A Metal-Insulator Transition in R2O2Bi with an Unusual Bi2- Square Net (R = Rare Earth or Y)

作者：Mizoguchi Hiroshi; Hosono Hideo^*

来源：Journal of the American Chemical Society, 2011, 133(8): 2394-2397.

DOI：10.1021/ja111015p

A series of tetragonal ThCr2Si2-type compounds, R2O2Bi (R = rare earth or Y), are synthesized in which an unusual Bi2- anion forms a square net layer that is sandwiched between (R2O2)(2+) fluorite layers. Two-dimensional (2D) electronic bands around the Fermi energy are predominantly composed of 6p(x)6p(y) orbitals in the Bi2- square net, which contains a positive hole per Bi2- 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.

• 出版日期2011-3-2