MAGNETIC PROPERTIES AND CRYSTALLIZATION OF RAPIDLY QUENCHED(Fe_(1-x)Ga_x)_(77.5)Nd_4B_(18.5) ALLOYS

The Curie temperature increases but crystallization temperature decreases with the in-crease of Ga content,x,of amorphous(Fe_(1-x)Ga_x)_(77.5)Nd_4B_(18.5) alloys.The averagemagnetic moment of Fe atoms is almost a constant.By X-ray diffraction and ther-momagnetic measurements,the crystalline phases of the alloys,an unknown phase andα-(Fe,Ga)besides Fe_3 B as major one,were identified.The relationship between roomtemperature coercive field and Ga.content was also studied.     

非晶态Nd4Fe77.5（B1—xCx）18.5合金的磁性和晶化

用急冷方法制备的Nd_4Fe_(77.5)(B_(1-x)C_x)_(18.5)合金带、当x<0.6时为非晶态,x>0.8时是晶态,表明用碳替代硼会使合金的非晶形成能力变差,分析了热处理样品中的晶化相组成。     

快淬（Fe1—xGax）77.5Nd4B18.5合金的磁性及其晶化行为

研究了快淬(Fe_(1-x)Ga_x)_(77.5)Nd_4 B_(18.5)合金的磁性,晶化行为,以及Ga含量和热处理对其硬磁性和相组成的影响,结果表明随着Ga含量x的增加,非晶态样品的Curie温度提高,而晶化温度降低,Fe原子的平均磁矩近似为一个常数,用X射线衍射和热磁测量分析了热处理后样品的结晶相,还研究了室温矫顽力与Ga含量的关系。     

TRANSFORMATION OF Nd_(14)Fe_(73)Co_6B_7 ALLOY UNDER HYDROGEN TREATMENT

The phase constitution and variation of Nd_(14)Fe_(73)Co_6B_7 alloy after hydriding and subsequentdehydriding treatment at 770℃ have been investigated respectively by means of X-raydiffraction,SEM,TEM and magnetic measurement techniques.The original coarse,as castgrain structure,is dissolved into α-Fe,Nd hydride and Fe_2B mixture with average dimensionof 0.1 μm,during hydriding process,and subsequently the triphase mixture recombined intofinely unique Nd_2Fe_(14)B phase with dimension of 0.3 μm by desorbing the hydrogen.It wasfound that the Nd-rich phase distributed at the boundary of as-cast grain structure diffusedinto matrix Nd_2Fe_(14)B grain during hydriding.It remains during dehydriding and distributehomogeneously around some colonies composed of fine grains of Nd_2Fe_(14)B.     

氢作用下Nd14Fe73Co6B7的相转变

利用X射线衍射、透射电子显微镜、扫描电镜及磁测量技术观察和分析了Nd_(14)Fe_(73)Co_6B_7合金于770℃吸氢后相结构组成与变化发现铸锭中的Nd_2Fe_(14)B基体吸氢后分解成约为0.1μm的NdH_2,α-Fe和Fe_2B三相混合物,脱氢后重新结合的Nd_2Fe_(14)B相尺寸约为0.3μm;铸锭中分布在基体相周围的富Nd边界相在吸氢时扩散入Nd_2Fe_(14)B基体,在脱氢过程中保留下来,均匀地分布在由若干Nd_2Fe_(14)B细小晶粒组成的晶粒团周围     

MAGNETIC PROPERTIES OF Nd_2(Fe_(1-x)M_x)_(14)B(M=C,Si)ALLOYS

The magnetic properties of Nd_2(Fe_(1-x)M_x)_(14)B(M=C and Si) compounds have been investi-gated.Substituting Fe by small amount of metalloid C and Si atoms,the compounds are intetragonal structure and have uniaxial anisotropy.The substitution of C for part of Fe de-creases the Curie temperature of the compounds and the intrinsic coercivity of bond samples atlow temperature.The replacement of Fe by Si makes the Curie temperature increase with amaximum at the vicinity of x=0.15.When the range of the content of Si is 0≤x≤0.10,thecoercivity distinctly increases at room temperature.from 62.7 kA/m at x=0 to138.7kA/m at x=0.06,where the residual magnetization has a maximum:in the mean timethe saturation magnetization decreases only by a small amount.     

Nd_2(Fe_(1-x)M_x)_(14)B(M=C,Si)合金的磁性

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。     

DISACCOMMODATION OF INITIAL SUSCEPTIBILITY IN AMORPHOUS Fe_(90-x)Ni_xZr_(10) ALLOYS

The disaccommodation(DA)measurements of initial susceptibility were performed inamorphous Fe_(90-x)Ni_xZr_(10)(x=10,20,30)alloys.The DA was measured for two differentamorphous states:as-quenched and pretreated at 537 K for 45 min.For all the as-quenched samples,in the isochronal spectra of DA a well defined relaxation peak around350 K is accompanied by a samll but distinct peak near the Curie temperature ofFe_(90)Zr_(10) phase(T_c=230 K).The reversibility and annealing effect on DA are analyzedwithin the framework of two-level model.The fits of the theory to the experimentaldata of reversible relaxation processes gave a spectrum,of activation energies and pre-exponential factor.     

非晶(Fe_(80)Ni_(20))_(78)Si_(22-x)B_x合金的磁矩与Curie温度

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     

Y2Fe17—xMnx的结构和磁性

Ｘ射线衍射证实了Ｙ２Ｆｅ１７－ｘＭｎｘ的结构与Ｙ２Ｆｅ１７相同Ｙ２Ｆｅ１７－ｘＭｎｘ化合物晶格常数，居里温度，饱和磁化强度和研究结果表明：晶格常数并非随Ｍｎ含量的增加而连续增大，而是在ｘ＝２．０处出现一最小值。     

Nd_2(Fe_(0.9)Si_(0.1))_(14)B的中子衍射研究SCIEI

本文用中子衍射对Nd_2(Fe_(0.9)Si_(0.1))_(14)B在室温及77K进行了测量,用衍射峰的形状分析法进行了数据拟合。结果表明,在室温,Si择优占据4c,8j_1及16k_2晶位;Nd与Fe的磁矩平行于C轴排列。在77K,Si仍择优占据上述三个晶位。算得的Nd磁矩的方向偏离C轴37.8°。     

（Sm_（1－x）Y_x）_2Fe_（17）N_y的Mossbauer谱研究

通过Ｍｏｓｓｂａｕｅｒ谱等研究（Ｓｍ１－ｘＹｘ）２Ｆｅ（１７）Ｎｙ的磁性。结果表明：Ｓｍ次格子的单轴各向异性较强，对总的各向异性贡献起主导机制；Ｙ原子的择优占位导致晶体结构的变化，而对各向异性的影响较小。     

非晶态Fe_(90-x)Si_xZr_(10)合金的磁矩,Curie温度和自旋波激发

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。     

THERMAL DEMAGNETIZATION AND RANDOMNESS OF DOMAIN NUCLEATION OF SINGLE PHASE Nd_2 Fe_(14) B

Based on the observation of temperature variation of both domain structure and magnetic con-trast.the thermal demagnetization and randomness of domain nucleation was discussed.     

间隙碳原子对（Er1—xSmx）2Fe17Cy化合物形成,结构与磁性的影响

用快淬方法制备了单相（Ｅｒ１－ｘＳｍｘ）２Ｆｅ１７ｃｙ（ｘ＝０．２，ｙ≤３．０；ｘ＝０．５，ｙ≤２．０）化合物，研究了它们的形成、结构、稳定性及内禀磁性。结果表明，它们在高温是稳定的，随碳含量的增加，晶体结构由六角的Ｔｈ２Ｎｉ１７型向菱方的Ｔｈ２Ｚｎ１７型转变。间隙碳原子的引入导致了单胞体积的膨胀、室温饱和磁化强度和Ｃｕｒｉｅｉ温度的增加。当ｙ≥１．０时，（Ｅｒ１－ｘＳｍｘ）２Ｆｅ１７Ｃｙ样品在室     

非晶态Fe_（90－x）Co_xZr_（10）合金的Invar效应研究

研究了作晶态Ｆｅ_（９０－ｘ）Ｃｏ_ｘＺｒ_（１０）合金的磁体积效应和广义声子谱．通过热膨胀测量和磁测量给出了自发体积磁致伸缩ωｓ和平均磁矩μ_（ＦｅＣｏ）与平均价电子数Ｎ_（ｅｆｆ）的关系，发现ωｓ的峰值位置与μ_（ＦｅＣｏ）开始急剧下降的位置（Ｎ_（ｅｆｆ）＝８．１－８．２）相对应，从而证实了金属－金属型非晶态因瓦合金中的Ｉｎｖａｒ效应与铁磁态的不稳性有关．用非弹性中子散射方法测量了广义声子谱，从中观察到了与Ｉｎｖａｒ效应相关的声子谱软化现象．     

MAGNETIC PHASE DIAGRAM OF SmMn_2(Ge_(1-x)Si_x)_2 SYSTEM

1.IntroductionTheternaryRMn2X2compounds(Risrareearth,andXisGeorSi)crystallizeinthebodycenteredtetrag0nalThCr2Si2-typestructurewithspacegr0upI4/mmm,inwhichtheR,TandXatomsoccuPythe2a,4dand4csites,respectivelyl1t2].Theyexhibitillterestingmagneticpr0perties['].InSmMn2Ge2tlireedifferentmagneticorderingtypeshavebeendetermined:ferromagnetismfor153K相似文献   

超过冷条件下Fe_(83)B_(17)共晶合金的凝固行为及显微组织演化

采用深过冷技术研究了块体Fe_(83)B_(17)共晶合金在超过冷度条件下的凝固行为.该合金的组织演化规律为:当过冷度达到理论临界超过冷度(300K)时,组织为α-Fe相和Fe_2B相组成的共晶组织;当过冷度大于临界值达到386K时,组织粗化,为完全的非规则共晶,稳定相Fe_2B消失,亚稳相Fe_3B出现并且在室温下也不会分解;获得了460K的超过冷度以及亚稳相组织.并讨论了这些结果产生的原因.     

NANOCRYSTALLINE STRUCTURE AND INITIAL PERMEABILITY OF ANNEALED Fe_（73．5）Cu_1W_3Si_（13．5）B_9 Alloy

ＮＡＮＯＣＲＹＳＴＡＬＬＩＮＥＳＴＲＵＣＴＵＲＥＡＮＤＩＮＩＴＩＡＬＰＥＲＭＥＡＢＩＬＩＴＹＯＦＡＮＮＥＡＬＥＤＦｅ_（７３．５）Ｃｕ_１Ｗ_３Ｓｉ_（１３．５）Ｂ_９ＡｌｌｏｙＺＨＡＮＧＸｉａｎｇｙｉ,ＺＨＡＮＧＪｉｎｇｗｕａｎｄＺＨＥＮＧＹａｎｇｚｅ?..     

MAGNETIC MOMENT,CURIE TEMPERATURE AND SPIN WAVE EXCITATION FOR AMORPHOUS Fe_(90-x)Si_xZr_(10) ALLOYS

The magnetization curves at 1.5 K and thermomagnetic curves for amorphous Fe_(90-x)Si_xZr_(10)(x=0,4,7 and 10)alloys prepared by the drum spinning technique have been measured with an extracting sample magnetometer.It is obtained that the average magnetic moment,,per magnetic atom and Curie temperature,T_c,in the amorphous FeSiZr alloys increase with increasing Si content.The and T_c are found to be quite small,compared with amorphous FeSiB alloys.This unusual behavior is suggested to be due to the presence of the Fe—Fe antiferromagnetic interactions.The temperature dependence of magnetization at lower temperature is in accordance with Bloch's T~(3/2) law.Calculation shows that the spin wave stiffness constant,D,increases with increasing Si content from 0.37 meV·nm~2 for x=0 to 0.538 meV·nm~2 for x=10.The values ofindicate that the range of the exchange interaction is roughly the mean atomic distance of nearest neighbours.