Mott transition in Ga-doped MgxZn1-xO: A direct observation

作者：Wei Wei; Nori Sudhakar; Jin Chunming; Narayan Jagdish; Narayan Roger J^*; Ponarin Dmtri; Smirnov Alex

来源：Materials Science and Engineering B-Solid State Materials for Advanced Technology, 2010, 171(1-3): 90-92.

DOI：10.1016/j.mseb.2010.03.078

• Mott transition
• Magnesium zinc oxide
• Gallium doping
• Thin film
• Pulsed laser deposition

This paper reports the direct evidence for Mott transition in Ga-doped MgxZn1-xO thin films. Highly transparent Ga-doped MgxZn1-xO thin films were grown on c-plane sapphire substrates using pulsed laser deposition. 0.1 at.%, 0.5 at.% and 1 at.% Ga-doped Mg-0.1 Zn0.9O films were selected for resistivity measurements in the temperature range from 250 K to 40 mK. The 0.1 at.% Ga-doped Mg-0.1 Zn0.9O thin film showed typical insulator-like behavior and the 1 at.% Ga-doped Mg-0.1 Zn0.9O thin film showed typical metal-like behavior. The 0.5 at.% Ga-doped Mg-0.1 Zn0.9O film showed increasing resistivity with decreasing temperature; resistivity was saturated with a value of 1.15 x 10(-2) Omega cm at 40 mK, which is characteristic of the metal-insulator transition region. Temperature-dependent conductivity sigma(T) in the low temperature range revealed that the electron-electron scattering is the dominant dephasing mechanism. The inelastic scattering time is found to vary as T-3/2.

• 出版日期2010-7-25