Size Dependent Magnetic and Optical Properties of Mn Doped Bi0. 9Ho0. 1FeO3 Nanoparticles

Abstract

In this work, Bi0.9Ho0.1Fe1 − xMnxO3 (x = 0.0, 0.05, 0.10, 0.15) nanoparticles have been successfully synthesized by sol–gel technique and subsequent annealing process. The variation of Mn doping in Bi0.9Ho0.1FeO3(BHFO)on the properties such as morphological, structural, magnetic, and optical have been investigated in this study. X-ray diffraction (XRD) patterns demonstrated that Mn substitution in BHFO led to a structural transition from rhombohedral (R3c) to orthorhombic (Pn21a) phase. The field emission scanning electron microscope (FESEM) showed that Mn doping decreased particle size and consequently higher percentages of Mn resulted agglomeration of particles severely. In this case particle sizes reduced from 60 nm to 30 nm. For Mn doping up to 5% in BHFO nanoparticles, the saturation magnetization (Ms) was enhanced, implying suppression of space modulated spin structure by structural transition. However, for a further increase of doping up to 15%, the Ms was started to decrease again. UV–Visible absorption spectra revealed that Mn substitution in BHFO led to strong reduction of band gap energy significantly. Band gap decreased from 2.9 to 2.38 eV on Mn doping, which allows the absorption of light extended to visible range.