郑朝贵
,
刘红平
,
乔芝郁
,
叶于浦
金属学报
借助DTA研究了LaCl_3-MgCl_2-LiCl三元体系的液相限,发现本体系内有对应于LaCl_3和α-固溶体(MgCl_2,LiCl)的两个液相面,一条二次结晶线和它的一个最低点M(63.8wt-％LaCl_3,2.0wt-％MgCl_2,34.2wt-％LiCl;492℃),结合液相限的测定,初步探讨了LnCl_3-MgCl_2-LiCl体系(Ln=La,Ce,Pr及Nd)相图中的某些变化规律。
关键词:
LaCl_3-MgCl_2-LiCl
,
LaCl_3
,
system
,
phase diagram
材料科学技术（英文）
Nanocrystalline epsilon and eta electron compounds and supersaturated solid solution of the Cu-Sn system have been prepared by mechanical alloying of elemental Cu and Sn powders. The atomic alloying and microstructure of the resultant alloys have been investigated by XRD, DSC and Sn-119 Mossbauer spectroscopy. A little amount of SnO2 was detected by Mossbauer spectroscopy, although no trace of diffraction peaks occurred in the XRD pattern. Thus the spectra for all the milled samples should be fitted using two quadrupole-splitting doublets: one corresponding to SnO2, the other corresponding to the resultant alloys. The composition dependence of the hyperfine parameters has been extensively discussed and explained well with respect to oxidation, surface effect resulting from grain refinement, coordination environment asymmetry and distortion caused or/and induced by mechanical alloying.
关键词:
system
Physica Status Solidi B-Basic Research
The magnetic properties of diluted mixed spin-1/2 and spin-1 Ising magnetic systems with crystal-field interactions on square lattice (z = 4) are investigated by the use of the effective-field theory with correlations. Especially the numerical results are given. The influence of concentrations of magnetic atoms P-alpha (alpha = A or B represent the two sublattices) and crystal-field interaction D on the properties of this system is discussed. The results show that the tricritical point, the reentrant phenomena and two compensation points exist.
关键词:
system
材料科学技术（英文）
The microstructure and phase relationship of (Dy0.65Tb0.25Pr0.1)Fe-x alloys in the composition range of 1.6 less than or equal to x less than or equal to 2.1 were investigated using optical microscopy, X-ray diffraction, DTA and EPMA techniques. The variations of microstructure and lattice parameter with the iron content, the effect of heat treatment on the microstructure and the phase relationship have been studied. The phase relationship in the vicinity of the Laves phase is proposed.
关键词:
system
材料科学技术（英文）
The structure and magnetostriction of R0.5Pr0.5Fex, (R = Dy0.7Tb0.3; 1.10 less than or equal to x less than or equal to 1.85) alloys were investigated. It was found that the matrix of are-melting R0.5Pr0.5Fex, alloys is the (Dy, Tb, Pr) Fe-2 phase with the MgCu2-type cubic structure and the second phase is rare earth-rich phase when x<1.25. In the range of 1.40 less than or equal to x<1.55, the second phase is (Dy, Tb, Pr)Fe-3 and it becomes the main phase when x >1.55. The crystalline structure of mechanically grinding R0.5Pr0.5Fex, alloys is similar to that of the are-melted alloys. The magnetostriction of the alloys increases with increasing Fe content when x less than or equal to 1.25 and decreases when x>1.25.
关键词:
system
Communications in Theoretical Physics
The influence of a bath consisting of both conduction electrons and Debye phonons on quantum tunneling in metals is studied by the perturbation approach developed by the authors. We find that the renormalized tunneling parameter and the condition of localization transition are modified in comparison with the results of a bath consisting of conduction electrons.
关键词:
system
ZHANG Cheng ZHANG Jishan GE Yunlong HU Zhuangqi Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015.China
材料科学技术（英文）
By laser heated pedestal growth method, Bi_2Sr_2CaCu_2O_(8+δ) as-grown fibers with different morphologies were solidified in non-equilibrium condition at the rates of 0.1～14mm/min.At low rates,a(Sr_(1-x)Ca_x)CuO_2 phase with long and straight strips in shape and a white Cu-rich phase having a morphology of globular shape were found. With the increase of solidification rates,the phase (Sr_(1-x)Ca_x)CuO_2 becomes thinner and the Cu-rich phase becomes smaller and dispersive.When the solidification rates were last.another unstable phase(Sr_(1-x)Ca_x)Cu_2O_3 occurred.In fact,the tran- sition of the semiconductive as-grown fiber to the superconductor is a peritectoid reaction influenced by the annealing temperature and time.
关键词:
Bi-Sr-Ca-Cu-O
,
null
,
null
,
null
,
null
YANG Yuanzheng MA Xueming DONG Yuanda Institute of Solid State Physics
,
Academia sinica
,
Hefei
,
China Professor.Institute of Solid State Physics Academic Sinica
,
Hefei 230031
,
China
金属学报(英文版)
Mechanical alloying was employed to produce super—saturated solution of Fe_1-xCu_x ,which is virtually immiscible under an equilibrium condition at ambient temperature.XRD results show that the solutions formed in the concentration ranges of x≤O.15 and x≥0.40 are of bee structure of x-Fe and fee structure of Cu,respectively.For the region in between (0.15
关键词:
mechanical alloying
,
null
,
null
,
null
,
null
HAN Haiou LIN Qin WEI Shoukun University of Science and Technology Beijing
,
100083
,
China.
材料科学技术（英文）
The phase diagram of the binary system MnO-Nb_2O_5 was studied by means of the differential thermal analysis(DTA),X-ray diffraction analysis and scanning electron microscopy(SEM).Thermodynamic da- ta of the new compounds 4MnO·Nb_2O_5 and MnO·Nb_2O_5were found as follows: 4MnO·Nb_2O_5:t_m=1398±2℃ △H_m=129000(J/mol) △S_m=77(J/mol,K) △G_m~o=129000-77T(J/mol) MnO·Nb_2O_5:t_m=1499±2℃ △H_m=86940(J/mol) △S_m=49.6(J/mol,K) △G_m~o=86940-49.6T(J/mol) The eutectic parameters for the system are given below: t_(E1)=1383±3℃ N_(E1(MnO))=0.896 t_(E2)=1312±2℃ N_(E2(MoO))=0.713 t_(E3)=1400±4℃ N_(E3(MnO))=0.231
关键词:
phase diagram
,
null
,
null
,
null
