Bulk magnetization, temperature - Dependent ac susceptibility and dc resistivity study on Mn0.7+xZn0.3SixFe2-2xO4 (x=0.0-0.3) spinel ferrites

Polycrystalline samples of spinel ferrite series, Mn0.7+xZn0.3SixFe2-2xO4 (x = 0.0, 0.1, 0.2, 0.3), were characterized by X-ray powder diffractometry, bulk magnetization at 300 K and 80 K, temperature dependence of low field ac susceptibility (chi(ac) (T)) (T - 300-525 K) and dc electrical resistivity (rho(dc) (T)) (T = 300-772 K) measurements. The variation of intrinsic and extrinsic magnetic parameters as a function of Mn-Si concentration (x) has been discussed. It is found that the system possesses a non-collinear spin arrangement and the canting angle increases with x. The Neel temperatures determined experimentally from susceptibility measurement adequately reflected the values calculated theoretically. The chi(ac) (T) curves revealed normal ferrimagnetic behavior while rho(dc) (T) depicts characteristic semiconducting behavior. The activation energy is found to increase with x that can be explained in light of the structural and microstructural parameters.