Microstructure and Optical Properties of CoxZn1-xGa2O4 (0 ≤ x ≤ 1) Nanoparticles

• Published in: European journal of inorganic chemistry 2013-03, Vol.2013 (8), p.1287-1293
• Main Authors: Duan, Xiulan, Yu, Fapeng, Wu, Yuanchun
• Format: Article
• Language: English
• Subjects: Annealing; Diffraction; Nanostructures; NMR spectroscopy; Photoelectron spectroscopy; Spectrum analysis; UV/Vis spectroscopy; X-rays
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201201004

CoxZn1–xGa2O4 (0 ≤ x ≤ 1) nanoparticles were synthesized by the sol‐gel method and characterized by X‐ray powder diffraction (XRD), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), 71Ga solid‐state NMR spectroscopy, and UV/Vis spectroscopy. The results show that the CoxZn1–xGa2O4 nanoparticles were successfully obtained when the annealing temperature was 500 °C or above. The crystallite size of the as‐prepared particles was 20–55 nm, and increased with increasing annealing temperature and decreasing x value. Zn2+ and Ga3+ ions were located in both the tetrahedral and octahedral sites in CoxZn1–xGa2O4 nanoparticles, and the inversion parameter (two times the fraction of Ga3+ ions in tetrahedral sites) decreased with increasing annealing temperature and increased with cobalt enrichment. The absorption spectra indicate that Co2+ ions are located in the tetrahedral sites as well as in the octahedral sites in the nanoparticles. The fraction of octahedral Co2+ ions decreased with increasing annealing temperature. Cobalt‐doped ZnGa2O4 nanoparticles were synthesized by the sol‐gel method, and their structure and optical properties were investigated. The cations in the nanoparticles occupied both the tetrahedral and octahedral sites of the spinel structure. The absorption bands at ca. 350 and 600 nm correspond to Co2+ ions in the octahedral and tetrahedral coordination sites, respectively.