Mössbauer analysis of Nd-Co M-type strontium hexaferrite powders with different iron content

C. HERME; S. E. JACOBO; P. G. BERCOFF; B. ARCONDO

La Plata

Conferencia; XI Latin American Conference on the Applications of the Mössbauer Effect (LACAME); 2008

The structural analysis of strontium hexaferrites SrFe$_x$O$_{19}$(for $x=12, 11$ and 10) and substituted samplesSr$_{0.7}$Nd$_{0.3}$Fe$_{12-y}$Co$_{0.3}$O$_{19}$ (for $y=0.3,1.3$ and $2.3$) prepared through the citrateprecursor method is shown. Nd and Co substitution modifiessaturation magnetization ($M_S$) and increases coercivity ($H_c$)in samples heat-treated at 1100$^{\circ}$C for two hours.M\"ossbauer analyses show different iron occupancy and theinfluence of the Fe$^{3+}$ content is particularly emphasized.Hematite segregation is observed for some compositions. Sampleswith low Fe$^{3+}$ content show the best magnetic properties withno secondary phase segregation.