Eur. Phys. J. B 39, 417-425 (2004)
https://doi.org/10.1140/epjb/e2004-00212-0

Mössbauer, X-ray diffraction and AC susceptibility studies on nanoparticles of zinc substituted magnesium ferrite

¹ Inter University Consortium for DAE facilities, 3/LB8, Bidhannagar, Kolkata 700 098, India
² Physics Department, Asutosh College, Kolkata 700 026, India
³ Central Glass and Ceramic Research Institute, Kolkata 700 032, India
⁴ LCMP, S.N. Bose National Centre for Basic Sciences, 3/JD, Bidhannagar, Kolkata 700 098, India

Corresponding author: ^a ddas@alpha.iuc.res.in

Received: 6 August 2003
Revised: 16 April 2004
Published online: 23 July 2004

Abstract

Nanoparticles of zinc substituted Mg-ferrite with compositions MgZn_xFe₂O₄ (x = 0.15, 0.30 and 0.50) having particle sizes in the range 6.4 nm to 21.4 nm prepared by the co-precipitation method were characterized by ⁵⁷Fe Mössbauer spectroscopy, X–ray diffratometry and AC magnetic susceptibility measurements. Mössbauer measurements at room temperature and down to 20 K clearly indicate presence of superparamagnetic particles in all the samples. AC magnetic susceptibility data show lowering of blocking temperature with decrease of particle size. Superparamagnetic relaxation was observed for larger particle size in samples with higher Zn content, which is attributed to the weakening of A-B exchange interaction in ferrite lattice due to replacement of Fe³⁺ in tetrahedral site by Zn²⁺ ions.