The temperature dependent magnetization of the (Ce,Nd) 2(Fe,Si,Mn) 17 intermetallic compounds were measured and analyzed by molecular field theory (MFT). The relationship between T C and the intrasublattic...The temperature dependent magnetization of the (Ce,Nd) 2(Fe,Si,Mn) 17 intermetallic compounds were measured and analyzed by molecular field theory (MFT). The relationship between T C and the intrasublattice coupling interactions was discussed. The two sublattice MFT model can well describe the temperature dependence of the magnetization for all the compounds investigated. Ce ion in (Ce,Nd) 2Fe 17 compounds does not simply dilute the magnetic structure, but is likely present in a mixed valence state. The substitution of Si for Fe strongly raises T C and the mean Fe moment remains unchanged for Ce 2(Si,Fe) 17 compounds, and the 3d exchange coupling constant J FF increases linearly. Mn decreases T C of Nd 2(Mn, Fe) 17 compound by reducing J FF .展开更多
采用溶胶凝胶法制备SrFe1-xCuxO3-δ多晶化合物,然后低温还原制备一系列掺Cu的Sr Fe O2氧化物,即Sr Fe1-xCuxO2(0≤x≤0.2)氧化物,对该氧化物的晶体结构和磁性能进行研究。X线衍射以及Rietveld结构精修分析结果表明:SrFeO2氧化物为层状...采用溶胶凝胶法制备SrFe1-xCuxO3-δ多晶化合物,然后低温还原制备一系列掺Cu的Sr Fe O2氧化物,即Sr Fe1-xCuxO2(0≤x≤0.2)氧化物,对该氧化物的晶体结构和磁性能进行研究。X线衍射以及Rietveld结构精修分析结果表明:SrFeO2氧化物为层状的四方晶体结构,空间点群为P4/mmm。Fe位掺Cu不会改变化合物的晶体结构,Cu原子完全占据Fe原子点阵位置。Sr Fe O2具有反铁磁性,奈尔温度为533 K,Fe离子的有效磁矩为4.6mB。低温区,x=0和0.1的化合物中还观察到新的磁相变。根据分子场理论,Sr Fe O2和Sr Fe0.9Cu0.1O2反铁磁交换作用的分子场系数分别为862和892。展开更多
文摘The temperature dependent magnetization of the (Ce,Nd) 2(Fe,Si,Mn) 17 intermetallic compounds were measured and analyzed by molecular field theory (MFT). The relationship between T C and the intrasublattice coupling interactions was discussed. The two sublattice MFT model can well describe the temperature dependence of the magnetization for all the compounds investigated. Ce ion in (Ce,Nd) 2Fe 17 compounds does not simply dilute the magnetic structure, but is likely present in a mixed valence state. The substitution of Si for Fe strongly raises T C and the mean Fe moment remains unchanged for Ce 2(Si,Fe) 17 compounds, and the 3d exchange coupling constant J FF increases linearly. Mn decreases T C of Nd 2(Mn, Fe) 17 compound by reducing J FF .
文摘采用溶胶凝胶法制备SrFe1-xCuxO3-δ多晶化合物,然后低温还原制备一系列掺Cu的Sr Fe O2氧化物,即Sr Fe1-xCuxO2(0≤x≤0.2)氧化物,对该氧化物的晶体结构和磁性能进行研究。X线衍射以及Rietveld结构精修分析结果表明:SrFeO2氧化物为层状的四方晶体结构,空间点群为P4/mmm。Fe位掺Cu不会改变化合物的晶体结构,Cu原子完全占据Fe原子点阵位置。Sr Fe O2具有反铁磁性,奈尔温度为533 K,Fe离子的有效磁矩为4.6mB。低温区,x=0和0.1的化合物中还观察到新的磁相变。根据分子场理论,Sr Fe O2和Sr Fe0.9Cu0.1O2反铁磁交换作用的分子场系数分别为862和892。
