Effect of annealing temperature and precipitation agent on the structure, optical and magnetic characteristics of dysprosium orthoferrite nanoparticles

Abstract

Powders consisting of DyFeO3 nanoparticles were obtained by the co-precipitation method using two different precipitating agents (NaOH (SH) and (NH4)2CO3 (AC) solutions) and followed by annealing for 1 h at 850, and 950 °C. Properties of the synthesized samples were characterized by FT-IR, PXRD, BET, TEM, UV-Vis DRS, and VSM analyses. The obtained data revealed that both calcination temperature and precipitation agent had notable influence on the structural parameters and properties of the synthesized DyFeO3 nanoparticles. Increasing the calcination temperature led to the increase of structural characteristics such as average crystallite size (DScher, DW-H, DRietveld, nm), lattice cell volume (V, Å), and crystallite phase content as well as in properties such as band gap energy value (Eg, eV), coercivity (Hc, Oe), remanent magnetization (Mr, emu∙g−1), and net magnetization (Mn, emu∙g−1). Additionally, when comparing samples calcined at the same temperature, DyFeO3-AC exhibited higher structural, optical, and magnetic properties compared to DyFeO3-SH. Moreover, the DyFeO3 nanoparticles synthesized in this study exhibited lower band gap energy (1.87–1.93 eV), coercivity (0.018–0.023 Oe), and remanent magnetization (2.82∙10−6–3.87∙10−6 emu∙g−1) values, but larger net magnetization (2.43–2.62 emu∙g−1) when compared to RFeO3 perovskites synthesized by different methods (R = La, Y, Ho, Dy, Eu, Tb).