No abstract

No abstract

No abstract

No abstract

In this study, FeB x Fe 2-x O 4 nanoparticles (NPs) were synthesized by the polyol method. The M-H hysteresis curves exhibit superparamagnetic characteristics that are both coercivity and remanent magnetization values are negligible. The particle size dependent Langevin function was applied to calculate the magnetic particle dimensions around 9 nm. The measured magnetic moments of NPs are in range of (1.52-2.2) l B and almost half or less with respect to 4 l B of bulk Fe ferrite. Magnetic anisotropy was specified as uniaxial and calculated effective anisotropy constants (K eff ) are between 43.3 9 10 4 and 19.4 9 10 4 emu/g. The UV-Vis diffuse reflectance spectroscopy and Kubelka-Munk theory were used to determine the optical properties. The estimated optical band gap values (2.15-2.48 eV) of FeB x Fe 2-x O 4 NPs are bigger with respect to reported values (1.88-2.12 eV) for Fe 3 O 4 NPs in the literature. The bigger E g values are mainly attributed to B concentration and partly to quantum confinement effect.