Ferrite magnetic nanoparticles in the composition Zn0.7Ni0.3Fe2O4 were synthesized by the polyol method, with an average size of 8 nm. Electron spin resonance (ESR) measurements were carried out at a frequency of 9.45 GHz in the 100–500K... more
Ferrite magnetic nanoparticles in the composition Zn0.7Ni0.3Fe2O4 were synthesized by the polyol
method, with an average size of 8 nm. Electron spin resonance (ESR) measurements were carried
out at a frequency of 9.45 GHz in the 100–500K temperature range. Obtained results exhibited a characteristic ESR signal in terms of resonance field, Hres, linewidth, DH, and peak ratio, R, for each magnetic phase. At low temperatures, the ferrimagnetic phase showed low Hres, broad DH, and asymmetric R. At high temperatures, these parameters exhibited opposite values: high Hres, small DH, and R1. For intermediate temperatures, a different phase was observed, which was identified as a superparamagnetic phase by means of zero-field cooling-field cooling and hysteresis loops measurements. The observed differences were explained in terms of the internal fields and especially due to the cubic anisotropy in the ordered phase
method, with an average size of 8 nm. Electron spin resonance (ESR) measurements were carried
out at a frequency of 9.45 GHz in the 100–500K temperature range. Obtained results exhibited a characteristic ESR signal in terms of resonance field, Hres, linewidth, DH, and peak ratio, R, for each magnetic phase. At low temperatures, the ferrimagnetic phase showed low Hres, broad DH, and asymmetric R. At high temperatures, these parameters exhibited opposite values: high Hres, small DH, and R1. For intermediate temperatures, a different phase was observed, which was identified as a superparamagnetic phase by means of zero-field cooling-field cooling and hysteresis loops measurements. The observed differences were explained in terms of the internal fields and especially due to the cubic anisotropy in the ordered phase
