[T16] Magnetic Materials

[15P-T16-02] Temperature Dependence of Magnetostrictive Properties of Cu_xCo_1-xFe₂O₄ Ferrites

*Shizuka Kosugi¹, Miu Hisamatsu¹, Shun Fujieda¹, Yuji Ohishi¹, Hiroaki Muta¹, Satoshi Seino¹, Takashi Nakagawa¹ (1.Osaka University, Japan)

Keywords:magnetostriction, magnetostrictive materials, temperature dependence, cobalt ferrites, copper substitution

The partial substitution of Cu for Co in the CoFe₂O₄ has been reported to improve magnetostrictive properties at room temperature. However, magnetostrictive materials are required to show superior magnetostrictive properties over a wide temperature range. In this study, the temperature dependence of magnetostrictive properties of the Cu_xCo_1-xFe₂O₄ was investigated. The strain as a function of magnetic field was measured up to 70 kOe for the CoFe₂O₄ and Cu_0.6Co_0.4Fe₂O₄ samples at different temperatures from 10 to 350 K. As a results, the saturation magnetostriction –λ_S value of the Cu_0.6Co_0.4Fe₂O₄ sample became larger with decreasing temperature and showed a maximum of 607 ppm at 100 K. Moreover, over the wide temperature range from 10 to 350 K, the –λ_S values of the Cu_0.6Co_0.4Fe₂O₄ sample were larger than those of the CoFe₂O₄ sample. Consequently, Cu_xCo_1-xFe₂O₄ ferrites are promising as rare-earth-free magnetostrictive materials.