Nd(Fe_(1-x)Co_x)_(10)V_2的Mssbauer谱

通过X射线衍射、磁测量和M ssbauer谱等测试方法研究了Nd(Fe1-xCox) 10 V2 的结构和磁性。结果表明 :Nd(Fe1-xCox) 10 V2 (x =0 ,0 .0 5 ,0 .1,0 .15 ,0 .2 )化合物的晶体结构均为ThMn12 型结构 ;随着Co含量增大 ,晶格常数将单调减少 ,居里温度Tc 呈单调增大 ,饱和磁化强度Ms 逐渐增加。Co部分取代Nd(Fe1-xCox) 10 V2 中的Fe原子 ,将择优占据 8i铁晶位。     

金属间化物Nd(Fe1-xCox)10V2的磁性能机制

通过X射线衍射,磁测量和Moessbauer谱测定了Nd(Fe1-xCox)10V2的结构和磁性。结果表明：Nd(Fe1-xCox)10V2(x=0,0.05,0.10,0.15,0.20)化合物的晶体结构均为ThMn12型结构;随着Co含量x的增大,晶格常数将单调减少。Co原子的将导致化合物各个Fe晶位上的磁超精细场值Bhf逐渐增加。Co部分取代Nd(Fe1-xCox)10V2中的Fe原子时,将择优占扰8i铁晶位。取向样品NdFe10V2的热磁曲线和变温Moessbauer谱研究结果表明,该化合物在T＝120K条件下存在自旋重取向现象。     

Nd（Fe1—xCox）10V2的Moessbauer谱

通过X射线衍射，磁测量和Noessbauer谱等测试方法研究了Nd(Fe1-xCox)10V2的结构和磁性。结果表明：Nd(Fe1-xCox)10V2(x=0,0.05,0.1,0.15,0.2)化合物的晶体结构均为ThMn12型结构；随着Co 含量增大，晶格常数将单调减少，居里温度Tc呈单调增大，饱和磁化强度Ms逐渐增加。Co部分取代Nd(Fe1-xCox)10V2中的Fe原子，将择优占据8i铁晶位。     

金属间化物Nd(Fe_(1-x)Co_x)_(10)V_2的磁性能机制

通过X射线衍射.磁测量和M(?)ssbauer谱测定了Nd（Fe1-Cox）10V2的结构和磁性.结果表明,Nd（Fe1-xCox）10V2（x=0,0.05,0.10,0.15,0.20）化合物的晶体结构均为ThMn12型结构;随着 Co含量x的增大,晶格常数将单调减少.Co原子的替代将导致化合物各个Fe晶位上的磁超精细场值Bhf逐渐增加.Co部分取代Nd（Fe1-xCox）10V2中的Fe原子时.将择优占据8i铁晶位.取向样品NdFe10V2的热磁曲线和变温M(?)ssbauer谱研究结果表明.该化合物在T=120K条件下存在自旋重取向现象.     

（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。     

ω相对Ti10V2Fe3Al合金性能的影响

采用透射电镜和金相显微镜等分析方法,研究Ti10V2Fe3Al合金ω相的形成规律和ω相对合金性能的影响.结果表明:当采用双重退火制度时,第一退火温度高于相变点或第二退火温度低于再结晶温度时,有大量ω相析出,此时合金的强度较高,但塑性非常差,无法满足使用要求;同时,在采用单重热处理制度的条件下,当处理温度高于相变点时,随着处理温度的升高,ω相析出迹象越明显,合金的塑性降低.     

非晶合金(Fe_(1-x)Co_x)_(86)Hf_7B_6Cu_1(x=0.4~0.6)磁性的EET理论研究

采用熔体单辊急冷法制备了非晶(Fe1-x Co x)86Hf7B6Cu1(x=0.4~0.6)合金,使用穆斯堡尔谱仪、透射电镜(TEM)和振动样品磁强计(VSM)对其进行了表征,穆斯堡尔谱和TEM结果表明所制样品均为非晶态。然后借助于固体与分子经验电子理论(EET理论),计算了非晶(Fe1-x Co x)86Hf7B6Cu1合金的价电子结构和磁矩,磁矩的理论计算值与实验测定值的误差小于10%,满足一级近似要求,实现了从价电子层次上计算非晶(Fe1-x Co x)86Hf7B6Cu1合金的磁矩,这对于优化非晶合金(Fe1-x Co x)86Hf7B6Cu1的软磁性能将具有理论指导意义。     

(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。     

EFFECTS OF HDDR PROCESS ON STRUCTURE AND MAGNETIC PROPERTIES OF Nd(Fe,Ti)_(12)N_δ PREPARED BY MECHANICAL ALLOYING

1.IntroductionThec0mparableintrinsicmagneticpropertiesofNd(Fe,Ti)12N6withthose0fNd,Fe,'B[1]andthep0ssibility0fpreparingmagnetswithahighc0ercivitybyusingmechanicalall0y-ing(MA)inc0mparis0nwithtraditionalmeth0dsl2'3'4'5]havedrawnextensiveattentioninexploringnewcandidates0frareearthpermanentmagnets(REPM).Especially,thiskindofcompoundhasalowrareearthc0ntent(withoutscarceSm),whichisofbenefittoalow-costproductionofREPM.Ontheotherhand,itiswellknownthatHDDRpreparati0nofREPMcanpr0ducec0ercive…     

Structural and magnetic properties of (Sm_0.5Nd_0.5)_2(Fe_(1-x)Co_x)_(17)compounds

The structure, magnetization, and magnetocrystalline anisotropy were investigated using X-ray diffraction, vibrating sample magnetometer, and AC susceptibility-meter. It is found that the microstructure of (Sm0.5Nd0.5)2(Fe1-xCox)17 alloys is an (Sm,Nd)2(Fe,Co)17 phase with the rhombohedral Th2Zn17-type structure. The Curie temperature Tc increases with the Co concentration increasing, and the magnetization first increases as the Co content increases in (Sm0.5Nd0.5)2(Fe1-xCox)17 alloys and then decreases slowly. The easy magnetization direction (EMD) of (Sm0.5Nd0.5)2(Fe0.25Co0.75)17 is along the c-axis and a strong enhancement of the crystalline anisotropy energy constant K is produced by the addition of some Co atoms. The anisotropy energy constant reaches the maximum when x = 0.75 and then decreases slowly with the Co content further increasing. The (Sm0.5Nd0.5)2(Fe0.25Co0.75)17compound is an optical candidate for the new permanent magnet, which possesses a high magnetization, a high Curie temperature,     

Chemical bond properties and M(?)ssbauer spectroscopy in (La_(1-x)M_x)_2CuO_4(M=Ba,Sr)

By using the average band-gap model, the chemical bond properties of (La1-xMx)2CuO4(M=Ba, Sr) were calcu-lated . The calculated covalencies for Cu-O and La-O bond in the compounds are 0.3 and 0.03 respectively. Mossbauerisomer shifts of 57Fe doped in La2CuO4 and 119Sn doped in La2CuO4 were calculated by using the chemical surroundingfactor defined by covalency and electronic polarizability. Four valence state tin and three valence iron sites were identifiedin 57Fe and 119Sn doped La2CuO4.     

Fe76Cu1Nb2V1Si10B10新型纳米晶合金的研究

报道了Ｆｅ７６Ｃｕ１Ｎｂ２Ｖ１Ｓｉ１０Ｂ１０新型纳米晶合金的研究结果。透射电镜和穆斯堡尔谱研究表明,合金经８３３Ｋ×３０ｍｉｎ真空退火,形成由平均晶粒尺寸为１８ｎｍ左右的α－Ｆｅ（Ｓｉ）相（～８６％）和少量非晶组成的显微结构。合金的饱和磁感应强度Ｂ５为１４２Ｔ,ｆ＝１ｋＨｚ时有效磁导率（μｅ）的最大值为５７８％×１０－３Ｈ／ｍ,铁损Ｐ１２／２ｋ≤２２３ｋＷ／ｍ３,Ｐ１１／１０ｋ≤２３７ｋＷ／ｍ３,Ｐ０５／２０ｋ≤１６５ｋＷ／ｍ３,Ｐ０２／１００ｋ≤３１５ｋＷ／ｍ３,矫顽力Ｈｃ≈１３Ａ／ｍ。合金具有明显的磁场处理效果,经纵向磁场退火后其Ｂ３０、Ｂｒ／Ｂ３０分别为１４９Ｔ、０９１,经横向磁场退火后其Ｂ３０、Ｂｒ／Ｂ３０分别为１３５Ｔ、００９。与Ｆｅ７３５Ｃｕ１Ｎｂ３Ｓｉ１３５Ｂ９相比,由于用Ｖ代替部分Ｎｂ,提高了钢水流动性,改善了快淬合金带材的力学特性,降低了成本。     

Microwave Dielectric Properties of Nd(Zn1/2Ti1/2)O3 Ceramics with V2O5 Additives

The microwave dielectric properties and the microstructures of V₂O₅-doped Nd(Zn_1/2Ti_1/2)O₃ ceramics prepared by conventional solid-state route have been studied. Doping with V₂O₅ (up to 6 wt.%) can effectively promote the densification of Nd(Zn_1/2Ti_1/2)O₃ ceramics with low sintering temperature. At 1300 °C, Nd(Zn_1/2Ti_1/2)O₃ ceramic when added with 6 wt.% V₂O₅ possesses a dielectric constant of 29.9, a quality factor (Q × f) value of 105000 GHz (at 8 GHz), and a temperature coefficient of resonant frequency of ?45 ppm/°C. These V₂O₅-doped Nd(Zn_1/2Ti_1/2)O₃ ceramics can be used in microwave devices.     

Application of Mossbauer spectroscopy of conversion and Auger electrons for the study of transformations on Fe electrode under conditions of passive-transpassive transition

Using Mossbauer spectroscopy of conversion and Auger electrons and X-ray photoelectron spectroscopy peculiarities and regularities in formation of composition and structure of the products of oxidation of ⁵⁷Fe samples in solutions of 0.1 N NaOH, a mixture of 1 N NaOH and 6 N NaNO₃, 1 N H₂SO₄, 0.1 N H₃BO₃, and 0.5 mol/L Na₂B₄O₇ in relation to the nature of corrosion medium and charge densities of anode polarization (10…12000 mA/cm²) corresponding to the region of passive-transpassive transition has been studied.