Electrical and optical characterization of Os-substituted rare-earth orthoferrite YbFeO${}_{3-\gamma }$ powders

The electrical properties of Os-doped YbFeO${}_3$ (YbFO) powders prepared by solid-state reaction have been studied by Impedance Spectrometer/Impedance Spectrometer. SEM, XPS and Raman spectroscopy were utilized for understanding chemical and structured analysis of the synthesized compounds. SEM images have revealed the void nature of the pellets. Furthermore, XPS studies have exhibited that Yb has 3 + valance state. It is also revealed that the oxygen vacancies concentration drops as the Os doping level raises by XPS analysis. The frequency dependency of loss-tan(δ) examination has demonstrated that the 5 mol% Os-substituted sample has the lowest loss-tan(δ) values at high frequency regions at 100 °C. It has been also realized that the 5 mol% Os-doped compound exhibits the highest resistivity among the samples. Raman spectroscopy examination has unveiled that the samples have similar space group. In addition, the optical band gap of the synthesized powders was also extracted via utilizing the Kubelka–Munk technique. It was realized that the band gap of YbFO slightly increases as the Os dopant ratio advances.