Effects of initial composition and oxygen pressure on formation of quasi-nanocrystalline Ba-Zn ferrite powders during self-propagating high-temperature synthesis

Quasi-nano sized Ba(x)Zn(1-x)Fe(2)O(4) ferrites were prepared using self-propagating high-temperature synthesis (SHS) with different initial compositions of BaO(2) and ZnO and various oxygen partial pressures of 0.25-1.0MPa. The combustion temperature and the combustion propagating rate increased with decreases in the molar ratio of barium oxide to zinc oxide and oxygen partial pressure in the ranges of 860-1208K and 4.9-6.0mm/s, respectively. As the oxygen pressure during SHS reaction increased from 0.25 to 1.0 MPa, the maximum magnetization (M(s)) level, the residual magnetization (M,) level and the coercive force ((i)H(c)) changed from 0.580 to 1.932 A.m(2)/kg, from 0.110 to 0.472A.m(2)/kg, and from 12.49 to 24.11 kA/m, respectively.