Doping effects on the dielectric properties of magnetoelectric GaFeO3 nanocrystals
Y. C. Lee (李雅琪)1*, Y. T. Chu (朱奕慈)1, W. L. Chen (陳雯嵐)1, T. C. Han (韓岱君)1
1Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan
* presenting author:李雅琪,
We have prepared a series of GaFe1-xMgxO3(0 ≤ x ≤ 0.1) and GaFe1-xZnxO3(0 ≤ x ≤ 0.05) nanocrystals and study the effects of doping on their structural and dielectric properties. All samples crystallize in the orthorhombic structure with space group Pc21n. The results show the dielectric constant was enhanced and the dielectric loss decreased in the doped samples. Among these samples, GaFe0.98Mg0.02O3 and GaFe0.99Zn0.01O3 have the highest dielectric constant and the lowest dielectric loss. In addition, it is found that with increasing Mg-content up to 0.02, the leakage currents decreased and reached the minimum value. We inferred the leakage currents result from the oxygen vacancies. The decrease of the leakage currents can be attributed to the substitution of Mg in the Fe site, decreasing the number of Fe2+ ions. The result decreased the electron hopping behavior between Fe2+ and Fe3+, and then reduced the sample’s leakage currents.

Keywords: nanocrystals, magnetoelectric, dielectric