Preparation of low loss Mn-Zn ferrite with complex oxalates

The complex oxalates for preparing Mn-Zn ferrite were made up by the reaction of ammonium oxalate to a sulfate solution derived from electrolytic Mn and industrial Fe and Zn as the raw materials. Control of composition was achieved by proper choice of the ratio of C2O4^-2to SO4^-2. The obvious advantage over conventional technique is its easy wash, simple processing, good reproducibility and low cost. Powder prepared with this method exhibited improved homogeneity, purity, reactivity and agglomeration. Samples without heat treatment possess superior quality of\mu_{i}=1800, \tan\delta/\mu_{i}=1.0\times10^{-6}(100KHz), D.F.=5×10^-6, αμ/μ/°C=1.0×10^-6(-10 ∼+55°C. Effect of heat treatment on μ-T curves is briefly described.