MAGNETOSTRICTIVE BEHAVIOUR OF R（Fe_（1－x）Al_x）_y ALLOYS（R＝Dy_（0．65）Tb_（0．25）Pr_（0．1））

ＭＡＧＮＥＴＯＳＴＲＩＣＴＩＶＥＢＥＨＡＶＩＯＵＲＯＦＲ（Ｆｅ_（１－ｘ）Ａｌ_ｘ）_ｙＡＬＬＯＹＳ（Ｒ＝Ｄｙ_（０．６５）Ｔｂ_（０．２５）Ｐｒ_（０．１））￥ＷＡＮＧＢｏｗｅｎ;ＷＵＣｈａｎｇｈｅｎｇ;ＺＨＵＡＮＧＹｕｚｈｉ;ＪＩＮＸｉｍｅｉ;ＬＩＪｉ...     

CHANGE OF BORIDE IN Fe_(70)Cr_(18)Mo_2SiB_9 WITH THERMAL TREATMENT

The formation of borides M_3B_2 M_2B_2 and M_(23)B_6 may be carried out from the melt-quenchedFe_(70)Cr_(18)Mo_2SiB_9 during 700—1150℃ annealing.As the temperature raising,the M_2B,themajority being Fe_2B.may be gradually replaced by Cr_2B via the co-existence between Fe_2Band Cr_2B.The Cr_2B may be formed by trans formation of Fe_2B through the atomic substitu-tion and structural adjustment.The thin slice of remaining Fe_2B is sandwiched between(100)faces of(Cr,Fe)_2B as stacking fault.The M_2B_2 is virtually composed of theMo_(1+x)(Fe,Cr)_(2-x)B_2 where x(0≤x≤1)increases with the increase of temperature.     

用Ga取代部分Fe对R3（Fe,Mo）29结构及磁性的影响

详细研究了Ｇａ取代Ｒ３（Ｆｅ,Ｍｏ）２９（Ｒ＝Ｓｍ,Ｙ）（Ｇａ＜０．１５）中的部分Ｆｅ对其结构和内禀磁性的影响,包括不同的Ｇａ取代对Ｒ３（Ｆｅ,Ｍｏ）２９化合物的晶胞常数、居里温度、饱和磁化强度、磁晶各向异性的影响。结果表明：在Ｒ３（Ｆｅ,Ｍｏ,Ｇａ）２９化合物中,随着Ｇａ含量的增加,晶胞体积膨胀,居里温度升高,饱和磁化强度下降,Ｆｅ原子的平均磁矩降低,Ｓｍ３（Ｆｅ０．９６６－ｘＭｏ０．０３４Ｇａｘ）２９化合物的各向异性由平面向锥面结构转变,继续增加Ｇａ含量,有可能出现单轴各向异性。     

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.     

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.     

含Fe和Mn的Ni_(30)Cu_(70)固溶体团簇模型与耐蚀性研究

提出了一个极限田溶体合金的团簇模型,在此基础上优化设计了添加Fe和Mn的Ni_(30)Cu_(70)(原子分数,%)固溶体合金成分.在该模型中,固溶的Fe和Mn以Ni为第一近邻形成12配位立方八面体原子团簇(Fe_(1-x)Mn_x)Ni_(12)而分散到Cu基体中,因此极限固溶体合金成分为[M_1/_(13)Ni_(12)/_(13)]30Cu_(70)=[(Fe_(1-x)Mn_xNi_(12)]Cua_(30.3),M=(Fe_(1-x)Mn_x).采用X射线衍射和电化学腐蚀测试等方法,研究了[(Fe_(1-x)Mn_x)Ni_(12)]Cu_(30.3)合金的微观组织与耐腐蚀性能的关系.实验结果表明,对应于极限同溶体状念的[(Fe_(0.75)Mn_(0.25))Ni_(12)]Cua_(30.3)合金,在3.5%NaCl溶液中具有相对好的耐腐蚀性能.     

电弧式快淬炉批量制备高性能(Nd,Zr)-Fe-B合金

采用电弧熔体快淬加后续晶化处理的方法批量制备了钕铁硼合金,研究了Zr、Nd元素含量对钕铁硼合金磁性能的影响。结果表明,添加的Zr原子能进入Nd：Fe14B相的晶格中,部分占据Nd原子的位置,从而提高Nd2Fe14B硬磁相的含量,因此显著提高(Nd,Zr)-F-B合金的磁性能。     

PHASE COMPONENT AND CURIE TEMPERATURE OF Nd_4(Fe_(1-x)Cr_x)_(77.5)B_(18.5)ALLOYS

1.IntroductionThenewhard-magneticNdFeBall0yswithlowNdc0ncentration(35at.%)havebeenobtainedbycrystallization0fam0rphous.ibbo.sI1-3].Theirmagneticpr0pertiesatr0omtemperatureareasfollows:coercivityHc=16O-24OkA/m,remanenceB,=1'2-1.25T,andmagneticenergy(BH).ax=64108kJ/m'.ThevaluesofB.and(BH).axaremuchhigherthanth0se0fthewidelyusedanis0tropic(Ba,Sr)Fe12Ol9ferritesandAlNiC0alloys.Inpreyi0uspapers['-'1,wehavereportedthestructuralandmagneticpr0perties.Recentlywestudiedtheinfluenceofthesubstit…     

Fe83Ga17R0.6(R=Ce,Tb和Dy)合金的微结构与磁致伸缩性能

为改善多晶Fe-Ga合金的磁致伸缩性能,在Fe-Ga合金中掺杂稀土Ce、Tb和Dy元素。 研究了Fe83Ga17和Fe83Ga17R0.6 (R=Ce、Tb和Dy)合金的结构和磁致伸缩性能。结果表明,Fe83Ga17合金由单一bcc结构Fe(Ga)固溶体相组成,而掺杂稀土后的Fe83Ga17R0.6合金中除保持bcc结构的Fe(Ga)固溶体相外,还出现了R2Fe17第二相。掺杂稀土后的Fe83Ga17R0.6合金磁致伸缩系数明显大于Fe83Ga17合金。掺杂不同种类的稀土元素对Fe-Ga合金磁致伸缩性能改善的程度不同。在外磁场为557 kA/m时,Fe83Ga17Ce0.6合金的磁致伸缩系数(206×10-6)明显大于Fe83Ga17Tb0.6 (165×10-6)和Fe83Ga17Dy0.6 (161×10-6)合金的磁致伸缩系数。     

Sm_2(Fe_(1-x)Cr_x)_(17)N_(～2.7)永磁材料的结构与磁性能

研究了Ｃｒ部分取代Ｆｅ对Ｓｍ_２（Ｆｅ_（１－ｘ）Ｃｒ_ｘ）_１７Ｎ_（~２．７）磁粉磁特性的影响．添加少量Ｃｒ（ｘ＝０－０．１），该化合物的结构不变化。随Ｃｒ含量的增加，它的Ｃｕｒｉｅ温度、各向异性场、饱和磁化强度、平均Ｆｅ原子磁矩和平均超精细场均有所降低．材料的单相性显著改善，矫顽力提高．Ｓｍ_２（Ｆｅ_（０．９５）Ｃｒ_（０．０５））_１７Ｎ_（~２．７）磁粉的矫顽力_ｉＨ_ｃ达到１５９２ｋＡ／ｍ．     

STRUCTURE AND MAGNETIC PROPERTIES OF Sm_2(Fe_(1-x)Cr_x)17N_(～2.7) MAGNETS

研究了Ｃｒ部分取代Ｆｅ对Ｓｍ_２（Ｆｅ_（１－ｘ）Ｃｒ_ｘ）_１７Ｎ_（~２．７）磁粉磁特性的影响．添加少量Ｃｒ（ｘ＝０－０．１），该化合物的结构不变化。随Ｃｒ含量的增加，它的Ｃｕｒｉｅ温度、各向异性场、饱和磁化强度、平均Ｆｅ原子磁矩和平均超精细场均有所降低．材料的单相性显著改善，矫顽力提高．Ｓｍ_２（Ｆｅ_（０．９５）Ｃｒ_（０．０５））_１７Ｎ_（~２．７）磁粉的矫顽力_ｉＨ_ｃ达到１５９２ｋＡ／ｍ．     

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°。     

STRUCTURAL RELAXATION OF AMORPHOUS ALLOYS Fe_(77.8)Si_(7.5)B_(14.7) AND Fe_(78.5)Si_(8.9)B_(12.6)

<正> 本文用Mossbauer技术结合DTA和电阻分析,对两种非晶态合金(Ⅰ)Fe_(77.8)Si_(7.5)B_(14.7)和(Ⅱ)Fe_(78.5)Si_(8.9)B_(12.6)的结构弛豫进行了研究。 Ⅰ和Ⅱ两种非晶态合金的DTA曲线如图1,晶化开始温度分别为530和500℃,晶化前均出现较长的放热峰,预示其结构弛豫过程中可能发生某种结构变化。     

退火温度对纳米晶Ni_(0.5)Zn_(0.5)Fe_2O_4吸波性能的影响

采用溶胶-凝胶自燃烧法制备了Ni_(0.5)Zn_(0.5)Fe_2O_4纳米晶,将其分别在550、800和1050℃下二次退火2h,利用XRD和微波矢量网络分析方法对二次热处理产物及其电磁性质进行了研究.结果表明,自燃烧后已形成完整的结晶尖晶石型Ni_(0.5)Zn_(0.5)Fe_2O_4纳米晶.在0.1～1.5 GHz的测试频率,纳米晶具有介电损耗和磁损耗,且随着热处理温度的升高,电损耗逐渐减小.在1050℃下退火后获得的Ni_(0.5)Zn_(0.5)Fe_2O_4纳米晶材料的μ'、μ"以及磁损耗正切tanδ_m明显大于在室温及550、800℃退火后的试样,在所测频率内具有优异的磁吸收性能.     

(Mn1-xFex)5Sn3合金晶体结构和居里温度

用粉末冶金法(磁场压制烧结)制备(Mn1-xFex)5Sn3(x=0.1～0.5)合金,对其晶体结构、居里温度进行研究。室温XRD分析表明,该系列合金均保持Mn5Sn3的InNi2型相结构,计算发现合金的晶格常数随着x量增大而减小。通过M-T曲线测量结果表明:居里温度TC在室温附近244～391K连续可调,且随着Fe含量的增加而提高,居里温度随成分近似呈线性变化;成分为(Mn0.70Fe0.30)5Sn3合金的居里温度为295K,在外加磁场为0～1.5T下,最大磁熵变约为0.87J·(kg·K)-1,是一种成本低廉的室温磁制冷候选材料。     

MOSSBAUER STUDIES OF Nd-Fe-B ALLOYS

对Nd_(15)Fe_(85-x)B_x(x=0-8)合金作了Mossbauer分析及磁测量,探讨了硼含量对结构的影响。 对于最佳磁性能的Nd_(15)Fe_(77)B_8合金,其Mossbauer谱可分解为6套铁磁亚谱和一套顺磁亚谱,分别对应于Nd_2Fe_(14)B四方相和富Nd相,并估计有6％的Fe原子处于富Nd相中。     

In-situ observation of magnetization reversal process of Sm(Co,Cu,Fe,Zr)_z magnets with different Fe contents

Sm(Co,Cu,Fe,Zr)_z magnets have drawn much attention for high-temperature applications due to their high Curie temperature,strong corrosion resistance and thermal stability.The effect of increasing Fe content on the distribution of elements and squareness(S_r) of demagnetization curves were investigated for two kinds of magnets with different nominal compositions of Sm(Co_(bal)Fe_(0.15)-Cu_(0.07)Zr_(0.03))_(7.8) and Sm(Co_(bal)Fe_(0.28)Cu_(0.07)Zr_(0.03))_(6.6) in this work.The magnetic properties of the magnets with higher Fe content fluctuate greatly after different solution treatments,indicating that they are more sensitive to the process temperature.The increase in Fe content can obviously enhance the cellular phase size.Meanwhile,inhomogeneous Cu distribution is observed in the Sm(Co_(bal)Fe_(0.28)-Cu_(0.07)Zr_(0.03))_(6.6) magnet,resulting in the different cellular structures and corresponding magnetic domain patterns in different regions in the inner grains.Furthermore,the lower Cu content regions are responsible for the wider magnetic domain,which have weaker resistance to applied magnetic field.As a result,S_r of demagnetization curve decreases with the increase in Fe content due to the inhomogeneous Cu distribution,which was confirmed by in-situ observation of electron probe micro-analyzer(EPMA) and magneto-optical Kerr optical microscope(MOKE).     

Fe78B13Si9纳米晶合金的热性能研究

采用适当的热处理工艺将相同成分的Fe_(78)B_(13)Si_9非晶态合金条带晶化制备成纳米晶合金;测定并研究了纳米晶合金的微观结构(晶体结构及尺寸)和一些结构敏感性能(热膨胀、比热),同时,将其与同样成分的非晶态、大晶粒状态合金的性能进行比较分析,认为由于纳米晶合金特殊的微观结构(短程无序),使其在性能上表现出与通常材料有很大差异。     

Cr含量对TiMn1.2-xCrxV0.25Fe0.05合金吸/放氢性能的影响

对名义成分为TiMn1.2-xCrxV0．25Fe0．05(x=0．0，0．1，0．2，0．3，0．4)合金的储氢性能进行了研究．结果表明，合金的晶格常数和晶胞体积随Cr含量的增加而增大；随着Cr含量的增加，合金的吸／放氢平台压力和滞后效应减小．随着cr含量的变化，TiMn1.2-xCrxV0．25Fe0．05合金112峰半高宽(FWHM)和晶格常数c／a比率的变化与该合金吸／放氢平台斜率的变化一致，表明合金的平台斜率与合金的品格畸变关系密切．TiMn1.0Cr0.2V0.25Fe0.05合金具有较大的储氢量、低的平台压力、小的滞后和斜率，适于作为质子交换膜燃料电池供氢源的储氢瓶应用．     

Ti含量对Ni53Mn23.5Ga23.5-xTix铁磁性形状记忆合金组织和性能的影响

采用光学显微镜、示差扫描热分析、交流磁化率测试和室温压缩试验等方法系统研究Ti含量对Ni53Mn23.5Ga23.5-xTix (x=0, 0.5, 2, 3.5, 8, 15)合金的显微组织、相变行为、力学行为和磁学特性的影响规律。结果表明：Ti元素在合金中的极限固溶度低于15%;随着Ti含量的增加,合金的相变温度和断裂强度及断裂应变先逐渐增加后降低,其断裂方式由沿晶断裂转变为穿晶断裂再到沿晶断裂;而合金的居里温度随Ti含量的增加逐渐降低