排序方式: 共有4条查询结果,搜索用时 0 毫秒
1
1.
1 Introduction UltrafineparticlesofmagneticmaterialssuchasFe,Co,Niandtheiralloyshavethepotentialapplicationsinmagneticrecording,ferrofluids,medicaldiagnosticetc..Themagneticpropertiesoffineparticlesdiffermagnificentlyfromthoseoflargeparticles,andtherelat… 相似文献
2.
1IntroductionIt is well known that the solubility of carbon in Fefor both body-centered-cubic (bcc) and face-centered-cubic (fcc) structures is very low, even in a liquidstate. The maxi mum solubility of carbon in ferrite isonly about 0 .1 atompercent .The difference of atomicradius between Fe and C is so large that C is em-bedded at the interstitial site in the bcc or fcc Fe lat-tice . Hume-Rothery rules suggest that the atomic sizeof the solute and solvent should differ by less than15 %to… 相似文献
3.
1 Introduction Fe Nialloyiswidelyusedassoftmagneticmaterialsforalongtime .Itsmagneticpropertiesasinitialperme abilityμiandcoercivityforceHcdependstronglyonthechemicalcompositionandtreatmentlikequenchingfromhightemperature .Asultrafineparticleisrevealedr… 相似文献
4.
Supersaturated solid solutions Fe1-xCx (0≤x≤0.9 ) of wide composition range have been prepared by mechanical alloying process. Nanocrystalline phase was formed for 0 ≤ x ≤ 0.67 and a large grain phase for 0.75 ≤ x ≤ 0.9. The large fraction of graphite volume puts off formation of nanocrystalline phase for high carbon content. In the large grain phase, magnetization follows simple magnetic dilution, and eoereivity He is mainly due to dissolution of carbon at grain boundaries. In the nanocrystalline phase the alloying effect of carbon is revealed by a distinct reduction of average magnetic moment. The increasing lattice constant with increasing carbon content is observed for x ≤ 0.5, suggesting that the high carbon concentration may enhance diffusion of carbon into the Fe lattice. It shows a discontinuity in the Hc variation with a grain size D of nanocrystalline phase. For small grain D below the critical value, Hc increases with D. For a large grain D, Hc decreases with increasing D. The solubility limit of carbon in a-Fe extended by nanocry- stalline phase formation is discussed. 相似文献
1