沈保根
,
章志英
,
郭慧群
,
赵见高
,
顾本喜
金属学报
非晶态Fe_(90-x)Si_xZr_(10)(x=0,4,7,10)合金是用单辊急冷方法制备的,用提拉样品磁强计测量了样品的磁化曲线和热磁曲线。发现每个磁性原子的平均磁矩μ和Curie温度T_c随Si含量的增加而增加,与相应的非晶态FeSiB合金相比,非晶态FeSiZr合金的μ和T_c明显偏低,认为这一反常现象是Fe-Fe原子间的反铁磁耦合的存在所致。低温下样品的磁化强度与温度的关系较好地符合Bloch T~(3/2)定律,得到自旋波劲度系数D从x=0时的0.37meV·um~2增加到x=10时的0.538meV·um~2,计算出交换相互作用范围都是在最近邻原子间的距离。
关键词:
非晶态
,
magnetic moment
,
Curie temperature
,
spin wave excitation
王高峰
,
松林
,
李福安
,
哈斯朝鲁
,
李新文
,
特古斯
金属学报
通过XRD和磁性测量对非化学计量比MnFe(P, Si, Ge)合金的相组成和磁性进行了研究.XRD分析表明, 所有样品都具有Fe2P型六角结构, 主相为(Fe, Mn)2(P, Si, Ge), 并存在少量的第二相(Fe, Mn)3(Si, Ge). 过量的Mn和Fe都会使合金的Curie温度降低, 由343 K(化学计量比)降低到294 K(过量Mn)和286 K(过量Fe); 过量的Mn能减小热滞, 而过量的Fe会使热滞增加; 磁熵变也有所减小,在1.5 T的磁场下, 最大磁熵变由5.2 J/(kgK)(化学计量比)减小到4.9 J/(kgK)(过量Mn)和3.8 J/(kgK)(过量Fe).
关键词:
MnFe(P
,
Curie temperature
,
thermal hysteresis
,
magnetic entropy change
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null
杨继廉
,
张百生
,
丁永凡
,
杨应昌
,
张晓东
,
潘树明
金属学报
用中子衍射法测定了R_2Fe_(17)N_x(R=Y,Dy,Nd)中N的占位及磁结构,初步讨论了N的占位对磁性能的影响
关键词:
中子衍射
,
Curie temperature
,
permanent magnet
邢峰
,
江潮
,
何文望
金属学报
本文研究了Nd_2(Fe_(1-x)M_x)_(14)B的磁性。少量类金属原子C和Si取代部分Fe,能形成四方结构,且具有单轴各向异性。碳取代Fe,使化合物的Curie温度降低,低温下粘结体样品的内禀矫顽力减少;而Si对Fe的取代可使Curie温度升高,并在x=0.15附近达到极大值。含Si样品在0≤x≤0.10范围内,矫顽力显著增加,室温下从x=0的62.7kA/m增加到x=0.06的138.7 kA/m,并且在x=0.06附近,剩磁有一个极值,饱和磁化强度减少不多。
关键词:
Nd-Fe-B合金
,
magnetic properties
,
Curie temperature
官可洪
,
卜晓东
金属学报
<正> 用液态快淬法制备非晶合金条带时,通过加入15—30％的B与Si等类金属含量是形成非晶状态的必要条件。但是,由于Si与B等类金属元素的加入,使非晶态合金的磁性受到明显的影响。 本文实验研究了Si与B含量间的相对变化对(Fe_(80)Ni_(20))_(78)Si_(22-x)B_x合金的饱和磁矩、平均原子磁矩与Curie温度的影响关系。利用电子转移模型与分子场近似理论定性的解释了(Fe_(80)Ni_(20))_(78)-Si_(22-x)B_x合金的磁矩(M_s)与Curie温度(T_c)随
关键词:
Fe-Ni-Si-B系合金
,
magnetic moment
,
Curie temperature
GUAN Kehong WANG Jun Northeast University of Technology
,
Shenyang
,
China GUAN Kehong
,
Associate Professor
,
Dept.of Material Science and Engineering
,
Northeast Univeristy of Technology
,
Shenyang 110006
,
China
金属学报(英文版)
The magnetic moment and the magnetostriction decrease slightly with the increase of total Si+B content.A maximum of the Curie temperature appears at about 25 at.-% of Si+B.The magnetic anisotropy is uninfluential by the content of Si+B,but much influnce by the demagnetization effect of streak.A qualitative explanation of the experimental phenomenon seems to be noted by the aid of the electron transition and structure model of amorphous al- loys.
关键词:
Fe-Si-B alloy
,
null
,
null
,
null
,
null
,
null
YANG Jilian ZHANC Baisheng DINC Yongfan China Institute of Atomic Engergy
,
Beijing
,
ChinaYANG Yingchang ZHANG Xiaodong Peking University
,
Beijing
,
ChinaPAN Shuming General Research Institute for Non-Ferrous Metals
,
Beijing
,
China associate professor
,
P.O.Box 275
,
Branch No.30
,
Beijing 102413
,
China
金属学报(英文版)
The N occupying sites and magnetic structures in R_2Fe_(17)N_x(R=Y,Dy,Nd)are de- termined by neutron diffraction.The effects of the site occupation of N on magnetic properties are discussed primarily.
关键词:
neutron diffraction
,
null
,
null
,
null
,
null
,
null
X.H. Wei
,
F. Ono
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
,
null
金属学报(英文版)
Measurements of magnetic susceptibility in mechanically alloyed Fe-Ni Invar alloys were taken under pressures up to 7.5GPa. The rate of decrease in the Curie temperature for 700℃ annealed specimen was larger than that annealed at 1000℃. This result can be explained by considering the fact that the width of the concentration fluctuation becomes larger in the specimen annealed at lower temperature.
关键词:
invar alloy
,
null
,
null
,
null
Hongwei QIN
,
Jifan HU
,
Juan CHEN
,
Hongdong NIU
,
Luming ZHU
,
Zhuo WANG
材料科学技术（英）
by Tb in (La1-xTbx)0.67Sr0.33MnO3, the room temperature magnetoresistance △R/R0 drops at first, then undergoes an increase near x≈0.1, and finally drops again. The value of room temperature magnetoresistance at a field H=12 kOe for (La1-xTbx)0.67Sr0.33MnO3 is -3.56%. The enhancement of the room temperature magnetoresistance induced by an appropriate Tb substitution in (La1-xTbx)0.67Sr0.33MnO3 is correlated with the shifts of the Curie temperature and metal-insulator temperature to near room temperature. The drop of the room temperature magnetoresistance at large Tb doping-contents may be due to its lower TC and TMI far from the room temperature.
关键词:
Magnetoresistance
,
null
,
null
,
null
