Synergistic effect of trivalent (Gd, Sm) and high-valent (Ti) co-doping on antiferromagnetic YFeO.

Monophasic polycrystalline powders of Y R Fe Ti O (R = Sm, Gd; = 0.05, 0.10, 0.15; = 0.05) were successfully synthesized a low temperature solid-state synthesis route. The X-ray diffraction and Raman spectroscopy studies indicate that all the calcined powders with R (Gd, Sm) at Y and Ti at Fe sites were crystallized in an orthorhombic phase associated with a change in lattice parameters. The Williamson-Hall method employed to calculate the strain revealed that the strain increased with the increased concentration of dopants ((Gd, Sm) at Y) compared to an increase in the size of crystallites, corroborating the findings of SEM. Analysis of diffuse reflectance spectra indicated a drop in bandgap from 1.93 eV to 1.86 eV and 1.96 eV to 1.91 eV for Gd, Ti co-doping and Sm, Ti co-doping respectively, demonstrating the capacity of the synthesized powders to absorb visible light. Absorbance spectra also revealed the existence of mixed states of Fe and Fe which was corroborated by XPS studies. The magnetic hysteresis loop analysis at room temperature illustrated that with co-doping, there is a strong enhancement in magnetization as well as coercivity, suggesting a strong transition from anti-ferromagnetic behaviour to ferromagnetic behaviour. Pertaining to the greatly improved optical and magnetic properties with the addition of (Gd, Sm) at Y and Ti at Fe sites, these materials are anticipated to be of potential use in various applications.