Structural, vibrational and magnetic properties of Cu-substituted Mn0.5Zn0.5Fe2O4 nanoparticles

Nanoparticles of quaternary Mn 0.5− x Cu x Zn 0.5 Fe 2 O 4 ferrite ( x = 0.05, 0.15, 0.25, and 0.35) have been investigated to understand the Cu role in modifying their static and dynamic magnetic properties. The substitution of Cu 2+ cation redistributes the other cations too. An attempt has been made to estimate the magnetization of the copper substituted ferrites based on redistributed cations. X-ray diffraction and Raman Spectroscopy investigations reveal that the as-prepared nanoparticles exhibit a single cubic mixed spinel phase. The Raman spectroscopy has established that Fe cations nearly 50% occupying at the tetrahedral site. The distribution of cations in Cu substituted Mn–Zn ferrite nanoparticles first estimated by Raman, Mossbauer, and X-ray photoelectron spectroscopic techniques have been subsequently refined by employing x-ray diffraction peaks intensity ratio method. The size of nearly spherical nanoparticles increases up to 22 nm with Cu 2+ concentration. Both magnetization and the spin ordering temperature enhances with an increase in Cu 2+ concentration (up to x = 0.25). The observed magnetization values match well with the estimated values. Lowering the line-width is about 620 Oe of FMR signal. The Lande’s g value increases up to 2.21 with an increase in Cu 2+ cation concentration suggests that copper enhances magnetic dipolar interactions superexchange interaction; the latter is evidenced by Arrott’s plot also. Magnetocrystalline anisotropy decreases with copper, confirm by the lowering of Canting angle. These nanoparticles can find their applications in devices operating in microwave regions.