Effect of rare earth oxides and La3+ ion concentration on some properties of Ni–Zn ferrites

摘要: Abstract The effect of both the rare earth ions and La 3+ ion concentration on dielectric properties Ni 0.5 Zn R y Fe 2− O 4 ; 0.0≤ ≤0.9, R=La, Yb, Dy Ce is studied. All samples are sintered at 1250 °C with heating rate 4 °C/min sintering time 35 h. ionic radii used (Yb , ) too large to occupy octahedral site. They form a secondary phases grain boundaries. X-ray data shows that lattice parameter for un- substituted ferrite sample larger than one, which main feature all elements. show pure has constant as well valence exchange respect one. This means introducing into decreases e ′ owing decreasing Fe–Fe interaction. lowest conduction attributed nature insoluble in spinel so it hindered Fe–R (3d–4f) coupling. can help obtain applicable ferrites.