Magnetic, optical and photocatalytic properties of yttrium doped KBiFe 2 O 5

In this work, we report the effect of doping with yttrium ions (Y 3+ ) on the magnetic and optical properties of KBiFe 2 O 5 (KBFO). Y doped KBFO with different mole percentage (KBi 1− x Y x Fe 2 O 5 with x = 0, 0.05, 0.10, 0.15) were synthesized by citrate assisted sol–gel route. Samples thus obtained were characterized by X-ray diffraction to establish their phase purity. Microstructural and compositional analyses were carried out using scanning electron microscope. Absorption spectra of the samples indicated a blue shift in the absorption spectra with Y doping and an increase in the energy band gap values. Y doped KBFO showed enhanced magnetic properties. Maximum magnetization at an applied field of 1.5 T showed steady increase with increase in the doping concentration. The values of magnetic moment at 1.5 T are 0.11 emu/g for x = 0, 0.16 emu/g for x = 0.05, 0.34 emu/g for x = 0.10 and 0.66 emu/g for x = 0.15. The remanent magnetization increased with increase in the Y content whereas coercivity decreased. Photoluminescence property of the samples was also evaluated. For an excitation wavelength of 450 nm, broadband emission spectra in the range 600–650 nm were observed for all samples. The evaluation of the photocatalytic activity of Y doped KBFO were also carried out by the degradation of methylene blue. Y doped KBFO showed enhanced photocatalytic efficiency which is attributed to an increase in the adsorption rate of the samples with Y doping.