Photoemission study of the filling-control metal-insulator transition in the two-dimensional system La1.17-xPbxVS3.17

Using photoemission spectroscopy, the electronic structure around the two-d imensional filling-control metal-insulator transition (MIT) of La1.17-xPbxV S3.17 has been studied. The density of state at the Fermi level disappears in going to the insulating phase, i.e., as x approaches similar to 0.17 or as the temperature decreases at x = 0.15. The chemical potential shift with carrier doping shows a finite jump between the electron- and hole-doped sa mples and is unusually suppressed around x = 0.17. The results are contrary to a rigid band picture and show the presence of a pseudogap in the metall ic phase. 2001 Elsevier Science B.V. All rights reserved.