Physical and Microwave Absorption Characteristics of High Powered Ultrasonically Irradiated Crystalline BaFe9Mn1.5Ti1.5O19 Particles

Abstract

Barium hexaferrite (BHF) with the chemical formula BaFe12O19 is a well-known permanent magnet and is still primarily used in various electrical devices. Because of its excellent magnetic properties, BHF is potentially one of the best candidates as a microwave absorber. For this investigation, the magnetic and microwave absorption characteristics of nanostructured BHF and BaFe9Mn1.5Ti1.5O19 were study. The high coercivity of BHF was substantially reduced through Mn-Ti partial substitution for Fe atoms with a minor reduction of its saturation magnetization. Nanostructured Mn-Ti–doped BHF was obtained through particle size reduction with high-powered ultrasonic irradiation. After 12 h of ultrasonic irradiation, the mean particle of BHF reduced to 61 nm from 380 nm, and the Mn-Ti–doped BHF reduced from 545 nm to 95 nm. The mean crystallite size of the two samples was 15 and 18 nm, respectively. Hence, the particles of both samples contained only a few crystallites. The characterization of reflection loss revealed that the highest absorption value achieved by the nanostructured BaFe9Mn1.5Ti1.5O19 sample was 19.75 dB at 13.6 GHz, and approximately 90% of the intensity of incoming electromagnetic waves was reduced by the material.

Keywords

• barium hexaferrite
• mechanical alloying
• reflection loss
• ultrasonic irradiation