Exchange-spring behavior in Ni<sub>0.3</sub>Cu<sub>0.2</sub>Zn<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub>/PbFe<sub>12</sub>O<sub>19</sub> nanocomposite
Kobra Khodayari, Ahmad Gholizadeh
Abstract
Abstract The structural and magnetic properties of the (1- x )Ni 0.3 Cu 0.2 Zn 0.5 Fe 2 O 4 /( x )PbFe 12 O 19 nanocomposites were investigated, where x is the weight percentage of PbFe 12 O 19 (hard phase) ranging from 0 to 100%. The magnetic measurement curves show a magnetic phase transition from soft to hard ferrimagnetic with an increasing weight percentage of the hard PbFe 12 O 19 phase. For weight percentages of 30%, 45%, and 60% of PbFe 12 O 19 , the M r / M s ratio is more than 0.5 and they show a normal single-phase magnetic behaviour, indicating the formation of a strong exchange coupling in these samples. Compared to the single-phase Ni 0.3 Cu 0.2 Zn 0.5 Fe 2 O 4 (soft phase), the saturation magnetization of the composites decreases significantly from 34.45 to 16.1 emu g −1 with increasing PbFe 12 O 19 content, while the coercivity increases from 62 to 861 Oe. Although increasing the PbFe 12 O 19 content reduces the saturation magnetization and increases the coercivity of the soft magnetic phase, this may provide a significant way to tune the magnetic properties with desired coercivity and saturation magnetization.