Magnetic and electric properties of cobalt doped GaFeO3 nanocrystals.
朱奕慈1, 鍾譯德1, 嚴鈞1, 陳雯嵐1, 韓岱君1*
1Applied Physics, National University of Kaohsiung, Kaohsiung, Taiwan
* presenting author:YIH-TSYR CHU,
We have prepared a series of GaFe1-xCoxO3 (0 ≤ x ≤ 0.1) nanocrystals and study the effects of doping on their structural, magnetic and electric properties. All samples crystallize in the orthorhombic structure with space group Pc21n. The magnetic characterization indicates that with an increase in the Co-content, the ferrimagnetic transition temperature of GaFe1-xCoxO3 (0 ≤ x ≤ 0.1) increases from 325 K to 355 K. The results show the dielectric constant was enhanced and the dielectric loss decreased in the doped samples. Among these samples, GaFe0.95Co0.05O3 have the highest dielectric constant and the lowest dielectric loss. In addition, it is found that with increasing Co-content up to 0.05, 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 Co 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, ferrimagnetic, dielectric, leakage currents