200 MeV Ag ion irradiation-induced modifications in structural, magnetic and dielectric properties of nanoparticles of Cu 0.2 Zn 0.8 Fe 2 O 4 ferrite.

The present investigation aims at studying the effect of swift heavy ion irradiation on the structural, magnetic and dielectric properties of the nanocrystalline Cu0.2Zn0.8Fe2O4spinel ferrite. The sample was synthesised using the sol–gel technique and then irradiated with the 200 MeV Ag+15ion beam. The Rietveld profile refinement of the X-ray diffraction patterns confirmed the cubic spinel structure of samples. The spherical morphology revealed through transmission electron microscopy images was consistent with the crystalline diameter. The overall magnetic behaviour pointed towards superparamagnetic relaxation at room temperature along with the significant increase in saturation magnetisation, coercivity and blocking temperature after irradiation. This could be attributed to the slight increase in the particle size and ion-induced modifications on the surface states of the nanoparticles. The enhancement in dielectric constant and loss tangent after irradiation could be attributed to the available Fe+2↔ Fe+3and/or Zn+2↔ Zn+3ion polarisation at the octahedral site, especially on grain boundaries of the sample. [ABSTRACT FROM AUTHOR]