Study of coercive force for yZnFe2O4-(1 − y)CoFe2O4 magnetic nanoparticles system

The coercive forces are taken out from the loops of magnetisation cycle for yZnFe 2 O 4 -(1 − y)CoFe 2 O 4 mixed magnetic nanoparticles system (y is the volume fraction of ZnFe 2 O 4 particles in yZnFe 2 O 4 -(1 − y)CoFe 2 O 4 magnetic nanoparticles mixed system). The results show that the coercive force of the system is increasing with the y decreasing and is interpreted by using particles chain model. The number of chains of particles under magnetic field is obtained by comparing the coercive force of the experiment and the theory of chain model. In yZnFe 2 O 4 -(1 − y)CoFe 2 O 4 magnetic nanoparticles mixed system, the coercive force comes from ferrimagnetic CoFe 2 O 4 nanoparticles, and paramagnetic ZnFe 2 O 4 nanoparticles make the chain length of the mixed magnetic system shorter than single CoFe 2 O 4 nanoparticles system.