Preparation of M-type Barium Hexaferrite and Studying Structural and Microwave Properties

Abstract

M-type Barium hexaferrite (BaFe12O19) were prepared using sol-gel auto composition methodwhich represent substantial magnetic materials and utilized as microwave absorbers and electronic devices. The powder was obtained after auto-composition procedure, then calcined at different temperature for 3hour. The XRD tests showed that difficultly of preparing the hexagonal phase directly after auto-composition procedure, but for the sample which calcined at 700 shows the presence of intermediate phase (BaFe2O4) and the existence of ( -Fe2O3) with barium hexaferrite (BaFe12O19) formation, when the temperature at 800 hexagonal phase formation was observed. The average grain size was estimated from SEM micrographs about (0.5, 0.6 and 0.8 µm) at respectively. Microwave absorbing characteristic studiedwithin X-band region using VNA (Vector Network Analyzer), it observed maximum reflection loss-26.61dB at 11.22GHz for the specimens that sintered at 1000 , while the specimens which sintered at 800 showed attenuation peaks exceeded -20 dB because it contains granules sufficiently small to approach single domain characteristic therefore itwas actively participating in the attenuation. The relative complex permittivity and permeability were calculated by using Nicolson-Ross-Wier (NRW) method for resonance attenuation peaks.