3.1. XRD analysis
The X-ray diffraction (XRD) pattern of Sn-substituted Ni-Zn ferrites with the chemical composition of Ni0.6-x/2Zn0.4-x/2SnxFe2O4 (NZSFO) are shown in Fig. 1. The XRD spectra were indexed and fcc cubic phase was identified. The structural parameters are calculated from the XRD data and have been discussed in Ali et al [6]. The lattice constants are calculated from the XRD data and represented in Table 1.
The distances between the magnetic ions at tetrahedral (A) and octahedral (B) sites have been calculated using the equation: L_A=a √3/4and L_B=a √3/2. The values are also depicted in Table 1. The hopping lengths of LAand LBdecrease with increasing Sn concentration might be cause of lattice parameters of the Ni-Zn ferrites decrease with increasing Sn4+concentration.
3.2 Magnetic Properties
A room temperature applied magnetic field dependent, H (up to 10 …show more content…
4(a). The decrease in the initial permeability of the Ni–Zn ferrites can be explained using the following equation μ^'=(M_s^2 D)/√(K_1 ), where µʹ is the initial permeability, MS the saturation magnetization, D the average grain size and K1 the magneto-crystalline anisotropy constant. As µʹ proportional to the square of the saturation magnetization and saturation magnetization is decreased with Sn concentration, hence the value of µʹ is expected to be decreased. Tetravalent Sn4+ ions have a strong octahedral-site preference, and the saturation magnetization decreased with the increasing Sn4+ substitution due to the weaker A–O–B super-exchange interaction results the value of µʹ decreases [34]. Fig. 4 (b) shows the relative quality factor NZSFO. The peak corresponding to maxima in Q-factor shifts to higher frequency range as Sn content increases. Q-factor has the maximum value of 5.2×103at f = 20 MHz for the x =0.05 sample. The Q-value depends on the ferrite microstructure, e.g. pore, grain size