Effect of indium-doping on the structural and dielectric properties of gallium ferrite nanoparticles

Yi-Hua Shih^1*, Jin-Te Wang¹, Chun-Chien Tseng¹, Yu-Wei Lue¹, Yu-Ru Wang¹, Yi-Ru Yang¹, Tai-Chun Han¹

¹Department of Applied Physics, National University of Kaohsiung, Kaohsiung, Taiwan

* Presenter:Yi-Hua Shih, email:a1084356@mail.nuk.edu.tw

In this study, we prepared a series of Ga_1-xIn_xFeO₃ (GIFO, 0 ≦ x ≦ 0.15) nanoparticles by sol-gel method. Impact of indium (In) on structural and dielectric properties of gallium ferrite nanoparticles has been investigated. All GIFO samples crystallize in the orthorhombic structure with Pc2₁n space group, as confirmed by X-ray diffraction and Raman spectroscopy. In addition, the average crystallite size (D) and lattice strain (k) of GIFO was estimated by using Debye-Scherrer formula and Williamson-Hall (W-H) method. It has shown also by increasing In-content, the average crystallite size decrease, while the lattice strain increases. The dielectric spectrum of the GIFO samples was obtained, the strong frequency-dependent dielectric constant, considerably high value at low frequency and low value at high frequency, may be due to the Maxwell-Wagner polarization effect. Interestingly, the dielectric characterization also indicates that the sample of Ga_0.95In_0.05FeO₃ exhibits the largest dielectric constant at low frequency. Furthermore, it was found that In-doping in GaFeO₃allows decreasing the leakage current density. This can be attributed to the variation of Fe³⁺distribution difference between the tetrahedral and octahedral sites after indium-doping.

Keywords: nanoparticle, gallium ferrite, structure, dielectric constant