Abstract: In the research, some PEG-6000 was introduced during the preparation of Mn-Zn ferrite nanopowders by chemical co-precipitation and reflexing method, tried to form a protective layer around the Mn-Zn ferrite nanoparticles for the purpose of prohibiting their aggregation.The results proved that addition of PEG-6000 not only decreased size of the nanoparticles, but also effectively alleviated their aggregation.By using those Mn-Zn ferrite nanopowders as starting materials to mould and then sinter at suitable temperatures, it's found that initial permeability of the sintere samples parabolically varied with an increase in temperatures and reach the maximum at the sintering temperature of 1200 ℃.The PEG-6000 added samples presente the initial permeability about 20; higher than those without any PEG-6000.Those results should be attributable to improvement in stability of the nanopowders and homogeneity in microstructure of the sintered samples, together with decrease in their grain size, by PEG-6000.

Key words: In the research, some PEG-6000 was introduced during the preparation of Mn-Zn ferrite nanopowders by chemical co-precipitation and reflexing method, tried to form a protective layer around the Mn-Zn ferrite nanoparticles for the purpose of prohibiting their aggregation.The results proved that addition of PEG-6000 not only decreased size of the nanoparticles, but also effectively alleviated their aggregation.By using those Mn-Zn ferrite nanopowders as starting materials to mould and then sinter at suitable temperatures, it's found that initial permeability of the sintere samples parabolically varied with an increase in temperatures and reach the maximum at the sintering temperature of 1200 ℃.The PEG-6000 added samples presente the initial permeability about 20; higher than those without any PEG-6000.Those results should be attributable to improvement in stability of the nanopowders and homogeneity in microstructure of the sintered samples, together with decrease in their grain size, by PEG-6000.