Effect of Additive Oxides on Formation of Amorphous CoFe2O4 and Magnetic Properties

The authors studied conditions for preparation of amorphous CoFe
2
O
4
samples by adding either P
2
O
5
and MoO
3
, or P
2
O
5
and V
2
O
5
, or CaO and V
2
O
5
, followed by mixing, heat-fusing at from 1000 to 4000°C, and quenching in water. X-ray analysis indicated that samples formed by adding P
2
O
5
and MoO
3
were amorphous even when heat-fused at temperatures as low as 1000°C. The amorphous composition regions for each system were determined. Magnetization in all samples increases sharply at temperatures below 100 K, but Mössbauer Spectroscopy revealed paramagnetic behavior at room temperatute.