Intrinsic magnetic-optical features of Dy3+ ion substituted NiCuZn nanospinel ferrites via sonochemical approach

Abstract

Ni0·4Cu0·2Zn0.4DyxFe2-xO4 (x ≤ 0.10) (NCZDy) nanospinel ferrites (NSFs) were prepared by an ultrasonication approach assisted sol-gel synthesis methodology. The cubic spinel structures of products were verified by XRD (X-ray powder diffraction) study. Intrinsic vibrational absorption bands of nanoparticles for their octahedral band (υ2) at 417 cm−1 and tetrahedral (υ1) band at 563-580 cm−1 were detected by FT-IR (Fourier-transform infrared) analysis. Magnetic studies by VSM (Vibrating sample magnetometry) confirmed the soft ferromagnetic nature of all products at 15 K and 300 K temperatures. As the amount of Dy3+ rises, saturation and remanent magnetization (Ms and Mr) values first increase for x = 0.02 composition; then they start to decrease with further rising the Dy3+ content. FC (Field-cooled) and ZFC (zero field-cooled) magnetization studies reveal that the irreversible temperature is above 300 K and the samples display spin glass behavior. Mössbauer spectra (MOS) were acquired to calculate hyperfine parameters by room-temperature (RT) spectra fitting and results indicated Dy3+ ions occupy octahedral sites. The optical investigation showed NCZDy (x ≤ 0.10) NSFs carry out a direct band character, and band gap values lay between 1.69 and 2.33 eV. All samples absorb the light within the visible region which is evident from the % Diffuse Reflectance Spectroscopy (DRS) results.