Temperature Dependence of Magnetostrctive Properties of Cu<sub>0.6</sub>Co<sub>0.4</sub>Fe<sub>2</sub>O<sub>4</sub> and CoFe<sub>2</sub>O<sub>4</sub> below Room Temperature

The temperature dependence of the magnetostrictive properties of Cu0.6Co0.4Fe2O4 and CoFe2O4 samples was investigated. At 300 K, the strain magnitude of the Cu0.6Co0.4Fe2O4 sample increased with increasing magnetic fields and reached a maximum value at approximately 0.8 T. Upon further increasing the magnetic fields, the strain magnitude gradually decreased and almost saturated at 7 T. Compared to the CoFe2O4 sample, the Cu0.6Co0.4Fe2O4 sample exhibited a more pronounced increase in the strain magnitude as the temperature decreased. In addition, the strain magnitude at 7 T of the Cu0.6Co0.4Fe2O4 sample exhibited a clear maximum at 100 K, unlike that obtained of the CoFe2O4 sample. The Cu0.6Co0.4Fe2O4 sample showed a strain of approximately 911 ppm at 100 K by changing the direction of 7 T magnetic field, which is significantly larger than that of the CoFe2O4 sample. Thus, the Cu0.6Co0.4Fe2O4 sample showed a larger strain magnitude than the CoFe2O4 sample in the temperature range of 10–300 K. Therefore, the partial substitution of Cu for Co is very effective in enhancing the magnetostrictive properties of CoFe2O4 across a wide temperature range, including room temperature.