Ultrafine BaFe 12O 19 powder synthesised by mechanochemical processing

Abstract

Ultrafine BaFe 12O 19 powder has been synthesised by a novel mechanochemical preparation method. Mechanical milling of 1.2BaCl 2 + 12FeCl 3 + 38.4NaOH led to a mixture of NaCl and iron and barium hydroxide or oxidehydroxide. The formation of BaFe 12O 19 required annealing at 800°C in air. A significant reduction of particle size was achieved by dilution with NaCl. High coercivity values above 5 kOe were measured for BaFe 12O 19 platelets of 20–100 nm in diameter and 10–20 nm thick.