The role of Os substitution on structural, magnetic, and optical features of LuFeO3

The powders of LuFeO3 and LuFe1-xOsxO3 (x = 0.05 and 0.10) were fabricated by using solid-state technique. The presence of particle agglomeration as well as the porosity of the analyzed materials have been shown via scanning electron microscope (SEM) studies. The oxidation states of the constituted elements in the fabricated samples have been determined with X-ray photoelectron spectroscopy (XPS) studies. It has been realized that the Lu has 3+, Fe accommodates both 2+ and 3+ valence stated in three samples. In addition, the oxidation state of Os has been identified as 4+ in the Os doped samples. It has been demonstrated that the Raman peak intensity of the Os substituted samples declines with Os presence. Furthermore, it has been seen that the peaks shift to lower wavenumber values in the Os doped specimens. Magnetic studies performed via vibrating sample magnetometer (VSM) found that the Os doping increases not only Hc but also Mr values at 10 K and 100 K, yet Hc and Mr values for undoped LFO at 300 K are higher than the Os doped samples. This rise in Hc and Mr values might be attributed to 1) deviations in the tilted angles of Fe3+ moments and 2) the evolution of energy of magnetocrystalline anisotropy. Moreover, the influence of Os doping on the optical band gap of LFO was determined. It exhibited that the optical band gap of LFO increases as the Os doping ratio elevates from 2.19 eV to 2.22 eV.