Paramagnetic Dy-doped ZnO grown by pulsed-laser deposition
Fang-Yuh Lo1*, Yi-Chieh Ting1, Kai-Chieh Chou1, Cin-Wei Ye1, Ming-Yau Chern2, Hsiang-Lin Liu1
1Department of Physics, National Taiwan Normal University, Taipei City, Taiwan
2Department of Physics, National Taiwan University, Taipei City, Taiwan
* presenting author:Fang-Yuh Lo,
Dysprosium-doped zinc oxide (Dy:ZnO) thin films were grown by pulsed-laser deposition on c-oriented sapphire substrate at a temperature of 550°C under oxygen partial pressure of 3×10-1 mbar. Thickness of the films is 150 nm, and the doping concentration ranges from 1 to 10 at.%. Structural investigations revealed heavily distorted lattice without secondary phase. Optical properties showed clear evidence of point defects such as zinc vacancy and zinc interstitials. All Dy-doped thin films show paramagnetic magnetization loops at both T = 5 and 300 K. Long-range blocking-type ordering was observed for low Dy concentration where the highest ordering temperature is about 120 K.

Keywords: dysprosium, ZnO, paramgnetism, blocking-type ordering