High magnetostriction parameters of sintered and magnetic field annealed Ga-substituted CoFe2O4

Impact of substitution of the non-magnetic ion Ga3+ for Fe3+ on the magnetostriction parameters of CoFe2O4 has been investigated for samples prepared by a tartrate-gel method. All the Ga-substituted compositions in CoGaxFe2-xO4 (0 ⩽ x ⩽ 0.3) showed higher strain sensitivity (dλ/dH), at low magnetic fields, compared to that of the unsubstituted sample. The magnetostriction strain (λ) and dλ/dH of the composition CoGa0.1Fe1.9O4 could be enhanced from −228 to −296 ppm and −2.20 × 10−9 to −3.55 × 10−9 m/A, respectively, at low magnetic fields, after magnetic field annealing at 300 °C.