Magnetic and Structural Properties of Manganese Zinc Soft Ferrite for High-Frequency Applications

Abstract

Current work elaborates magnetic, microstructural, and thermal properties of Mn0.45Zn0.55Fe2O4 ferrite synthesized by the powder metallurgy method. Process parameters have been established to obtain ideal microstructure and magnetic properties at a frequency ranging from 1 kHz to 1000 MHz. Microscopic examinations revealed a uniform spinel structure containing grains size of 12 ± <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2 \,\mu \text{m}$ </tex-math></inline-formula> and free of nonmagnetic phases. X-ray diffraction studies evidenced cubic crystal structure for pure spinel MnZn ferrite. The Mn0.45Zn0.55Fe2O4 ferrite exhibits inductance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$A_{L}$ </tex-math></inline-formula> ) as 5425 nH, initial relative permeability ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu _{i}$ </tex-math></inline-formula> ) as 5877, core loss ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{c}$ </tex-math></inline-formula> ) as 60.422 W/kg, and saturation magnetic polarization ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$I_{s}$ </tex-math></inline-formula> ) as 3.680 kG at a 1000-MHz applied frequency state. Surface coating was applied on toroid shape samples, which revealed a uniform coating thickness ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$450 \,\mu \text{m}$ </tex-math></inline-formula> ) and tenacious appearance of coating layer. Thermal stability of coating was found to be stable up to 150 °C for 6 h. Coating exhibits 35±2 HV hardness and coefficent of friction (CoF) as 0.27, which indicates excellent adherence and high wear resistance of coating.