Electronic Phase Transition in Layered Materials 1T-TaS_{x}Se_{2-x} Probed by Cryogenic STM/STS

• Authors: T. Hasegawa , O. Shiino , W. Yamaguchi , T. Endo , H. Sugawara , K. Kitazawa
• Languages of publication: EN

Abstracts

EN

A metal-insulator transition, Mott transition, in layered materials 1T-TaS_{x}Se_{2-x} was investigated by cryogenic scanning tunneling microscopy/ spectroscopy. At 77 K, tunneling spectra in the insulating phase showed a conduction band with almost half filling, which becomes narrower as x decreases. Around the transition point x≈1.4 at 77 K, we observed a sign of gap opening without an overshooting peak at zero bias, supporting the Mott localization picture in which a carrier number vanishes at the transition point. From the site-specified scanning tunneling spectroscopy measurements, furthermore, electrons were found to localize at the charge density wave crest positions. In 1T-TaS_{2}, we have also found that both metallic and insulating phases coexist in a nanometer scale just above the transition temperature, 180 K. >From the minimum size of the insulating region, the coherence length of Mott insulating state was evaluated to be≈5 nm.

Keywords

EN

71.30.+h; 71.20.-b

Discipline

• 71.20.-b: Electron density of states and band structure of crystalline solids
• 71.30.+h: Metal-insulator transitions and other electronic transitions

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 1998
• Volume: 93
• Issue: 2
• Pages: 297-305

Dates

published

1998-02

Contributors

author

T. Hasegawa

• Materials and Structures Laboratory, Tokyo Institute of Technology, Nagatsutacho 4259, Midori-ku, Yokohama 226, Japan

author

O. Shiino

• Department of Applied Chemistry, University of Tokyo, Japan Science and Technology Corporation, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan

author

W. Yamaguchi

• Department of Applied Chemistry, University of Tokyo, Japan Science and Technology Corporation, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan

author

T. Endo

• Department of Applied Chemistry, University of Tokyo, Japan Science and Technology Corporation, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan

author

H. Sugawara

• Department of Applied Chemistry, University of Tokyo, Japan Science and Technology Corporation, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan

author

K. Kitazawa

• Department of Applied Chemistry, University of Tokyo, Japan Science and Technology Corporation, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan

Identifiers

DOI

10.12693/APhysPolA.93.297