Abstract
This paper studied the exchange coupling performance beside structural and microwave properties of SrFe12O19 (SFO) and x(CoTm0.01Tb0.01Fe1.98O4) (CoTmTb) (x <= 3.0) hard/soft ferrites nanocomposites (NCs). The structure and morphology of NCs were investigated by XRD, SEM, TEM and HR-TEM. Diffuse reflectance spectroscopic (DRS) measurements were applied on hexagonal ferrite, on spinel ferrite nanoparticles and on hard/soft NCs to specify the optical properties. Estimated E-g data are in a range between 1.32 and 1.79 eV. The magnetic properties were also inspected via measurements of magnetization (M) against magnetic field (H) at 300 K (RT) and 10 K (LT). The measurements performed at RT along with the plots of dM/dH versus H indicated that the NCs display good magnetic properties (exchange coupling behavior). The magnetic parameters such as (M-s, M-r, and H-c) show an enhancement in their values with an increasing the soft content at RT. Similarly, the maximum energy product (BH)(max) rises and reaches its max value for SFO/3(CoTmTb) NCs. Microwave properties of the SFO/x(CoTmTb) NCs were measured in the frequency range 33-50 GHz. From measured S11 and S21 parameters the main electrodynamic characteristics - permittivity and permeability (real and imaginary parts) were computed. (C) 2021 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.