LAUSR

Ferrite nanomaterials in the form of CoAg x Fe 2− x O 4 ( x  = 0.0, 0.03, 0.07, 0.1, and 0.2) have been prepared by the citrate autocombustion method. Structural analysis was carried out by x-ray diffraction. Fourier-transform infrared spectroscopy confirmed the formation of a spinel crystal structure. High-resolution transmission electron microscopy revealed the formation of particles with mixed morphologies. The average particle size ranged from 22 nm to 31 nm. Vibrating-sample magnetometry revealed that the saturation magnetization M s and coercivity H c were affected by the grain size variation. The electrical properties of the samples were investigated over the frequency range from 10 2  Hz to 10 5  Hz. Electric modulus analysis showed that the conduction was due to short-range mobility of charge carriers. The variation of the dielectric loss with frequency at different temperatures indicated two types of conduction mechanism. All these results suggest that the synthesized materials can be recommended for fabrication of exchange spring magnets and electrode materials.