Influence of Zr doping on the structural, magnetic and magnetoelastic properties of cobalt-ferrites

Cobalt-ferrite (CoFe2O4) has long been identified as a potential material for the magnetostrictive component of the torque sensor - for power-steering systems in automotive industries, owing to its superior strain sensitivity (d lambda k/dH). In this work we investigate the influence of Zr doping (in Fe site) on the structural, magnetic, and magnetoelastic properties of CoFe2O4. Zr-doped cobalt-ferrites, having nominal compositions Co(1+x)ZrxFe(2) O-2x(4) (0 <= x <= 0.2), were synthesized by conventional solid-state method. The X-ray spectral analysis indicated the presence of only cubic-spinel phase and the lattice parameter (a) increases from similar to 8.3769 angstrom (x = 0) to similar to 8.3921 angstrom (x = 0.2). Saturation magnetization (M-S), at similar to 4000 kA/m, and coercivity (H-C) increases from similar to 413 kA/m and similar to 4.456 kA/m respectively for x = 0 to similar to 540 kA/m, similar to 7.96 kA/m respectively for x = 0.2. A remarkable 300% increase in d lambda/dH was observed in Zr-doped cobalt-ferrite sample (x = 0.2) (similar to 3.32 x 10 (9) A (1) m) compared to that of pure cobalt-ferrite (similar to 0.8 x 10 (9) A (1) m). (C) 2015 Elsevier B.V. All rights reserved.