Microwave power, temperature, atmospheric and light dependence of intrinsic defects in ZnO nanoparticles: A study of electron paramagnetic resonance (EPR) spectroscopy

作者：Erdem Emre^*

来源：Journal of Alloys and Compounds, 2014, 605: 34-44.

DOI：10.1016/j.jallcom.2014.03.157

• ZnO
• EPR spectroscopy
• Defects
• Size-effects

In this work ZnO nanoparticles were synthesized by coprecipitation method. We investigated the reactivity of 0.24 mu m and 50 nm ZnO sample as bulk and nano-sized, respectively. According to core-shell model we designated the electron paramagnetic resonance (EPR) signal at g similar to 2.004 and g similar to 1.961 as surface defects and core defects, respectively. Dependency of intrinsic defects on the surface and core were investigated under various conditions such as changing of microwave power and temperature, different atmosphere and different light exposures. We found that under such condition core defects revealed more controllable property than the surface defects. Spin-lattice (T-1) and spin-spin (T-2) relaxation time were also calculated from microwave power dependency measurements and it is found out that both relaxation time lays around nano-second regime which is extremely short. However relaxation time T-1 can be longer under N-2 atmosphere after further annealing.

• 出版日期2014-8-25