Ultrafine powders have received considerable attention in the past few years because of their potential applications, such as magnetic recording materials, ceramics and catalysts [1]. As a superior perpendicular magnetic recording medium, the magnetic properties of the hexagonal ferrite BaFe^Oig or SrFe^OiQ have been extensively studied [2]. Several procedures have been employed to prepare SrFe^Oig samples, including solid-state reaction [3], copreci-pitation [4] and glass crystallization [5], in which the temperature was very high and controlling the grain size as well as the surface areas of SrFeiaOjg samples was not easy. In the study reported here, we tried to synthesize SrFe^Oig ultrafine powders at fairly low temperature (450 °C) by using polyvinyl alcohol (PVA; the polymerization degree was 2000). Thereafter, the magnetic and electron paramagnetic resonance (EPR) properties of the SrFei2Oi9 ultra-fine powders were investigated.
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