Pressure-induced Crossover from Variable Range Hopping to Electron-Electron Interaction in the Organic Conductor (DOET)_2BF_4

Access this Article

Search this Article

Author(s)

Abstract

This paper reports the pressure effect on resistivity in the quasi two-dimensional (2D) organic conductor (DOET)<SUB>2</SUB>BF<SUB>4</SUB> with orientational disorder of BF<SUB>4</SUB> anions. At ambient pressure, the resistivity shows metal–insulator transition at 80 K and 2D variable range hopping (VRH) conduction below 80 K. The insulating behavior is suppressed by applying pressure and the temperature dependence of the resistivity shows the crossover from the 2D VRH to the logarithmic divergence as applied pressure increases. From the observation of the positive magnetoresistance, the logarithmic divergence of the resistivity is not attributed to the Anderson localization, but to the effect of the electron–electron interaction. This crossover is simply understood in terms of the screening effect on the random potential by increase of bandwidth due to applied pressure. It is found that a value of sheet conductance at low temperatures above 8 kbar, where the insulating state is almost suppressed, approaches to the minimum conductivity for a metallic state, σ<SUB>min</SUB>=<I>e</I><SUP>2</SUP>⁄<I>h</I>=1⁄(25.8kΩ), first proposed by Mott.

Journal

  • Journal of the Physical Society of Japan

    Journal of the Physical Society of Japan 75(2), "24701-1"-"24701-6", 2006-02-15

    The Physical Society of Japan (JPS)

References:  35

Codes

  • NII Article ID (NAID)
    110004086877
  • NII NACSIS-CAT ID (NCID)
    AA00704814
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    00319015
  • NDL Article ID
    7813236
  • NDL Source Classification
    ZM35(科学技術--物理学)
  • NDL Call No.
    Z53-A404
  • Data Source
    CJP  NDL  NII-ELS  J-STAGE 
Page Top