Frequency dependence of the conductivity and dielectric constant of La2CuO4+y near the insulator-metal transition

✍ Scribed by C.Y. Chen; R.J. Birgeneau; D.R. Gabbe; H.P. Jenssen; M.A. Kastner; P.J. Picone; N.W. Preyer; Tineke Thio

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 135 KB
• Volume: 162-164
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(89)90578-9

✦ Synopsis

Measurements are reported of the conductivity and the dielectric constant (¢1) at frequencies (to) up to 20 MHz and magnetic fields up to 15 T for a single crystal of La2CuO4+y with y varied in the range 0.001 -0.01. The frequency dependence of the conductivity at low temperatures follows a power law, which is typical of conventional doped semiconductors. ¢1 at high to is independent of to and grows as the insulator to metal transition (IMT) is approached, but only for the electric field in the CuO2 layers, indicating that the IMT is two-dimensional. For the highest oxygen concentration, this excess ¢1 was reduced by a factor of 2 at a magnetic field of 15 T perpendicular to the CuO2 layers.