Study On The Phase Diagrams Of Fe-Pb-Sb And Nd-In-Sn Ternary Systems And On The Cystal Structures Of Some Compounds

Phase relations in the Nd-In-Sn ternary system at 773K 373K and in the Fe-Pb-Sb ternary system at 500K have been investigated in this work. Moreover, the crystall structures of SmCo9Si4 and CrFe3NiSn5 have also been studied. The main contents were as follows:1 The isothermal section of Fe-Pb-Sb ternary system at 500KPhase relations in the Fe-Pb-Sb ternary system at 500K have been investigated by means of X-ray diffraction technique and optical microscope. There are three three-phase regions, seven two-phase regions and five single-phase regions in this isothermal section. And at 500K, the solid solubility of Fe1+xSb which was determined by the varying of the lattice parameters is about 2.2at.% and the solid solubility of Sb in Pb is about 3.3at.% determined by the varying of the lattice parameters along with the vanishment of phase.2 The isothermal section of Nd-In-Sn ternary system at 773K and 373KPhase relations in the Nd-In-Sn ternary system at 773K (25 at.%Nd-100 at. %Nd) and at 373 K (0-25 at. %Nd) have been investigated by means of X-ray diffraction technique, differential thermal analysis and scanning electron microscopy. Fifteen binary compounds have been confirmed through our study which are Nd3Sn Nd5Sn3 Nd5Sn4Nd11Sn10 NdSn2 Nd3Sn7 Nd2Sn5 NdSn3 Nd3In Nd2In NdIn Nd3In5 NdIn3 B (In3Sn )and r (InSn4). Among them, Nd3Sn was a new binary compound in the Nd-Sn binary system and first reported here which has the same crystal structure type with Nd3In. Nd3Sn and Nd3In, NdSn3 and NdIn3 formed the continuous solid solubility respectively. The solid solubility of In in Nd3Sn7 is about 10 at. % and that of Sn in Nd3In5 is about 50at.%. NdSn and Nd3Sn5 have not been confirmed in this work. At the meantime, we find the NdSn2 has a solid soluble range from 57at.%Sn to 66.7at.%Sn. According to the results above, we constructed the phase diagram of the Nd-In-Sn ternary system at 773K and 373K. It consists of 21 single-phase regions, 50 two-phase regions and 12 three-phase regions. No ternary compounds were found.3 Crystal structure of the compound SmCo9Si4The crystal structure of the compound SmCo9Si4 has been studied by X-ray powder diffraction technique and refined by Rietveld profile fitting method. The compound has a tetragonal space group I4/mcm with the lattice parameters a=7.7858(1)A, c=11.5054(2) A, z=4, Dcaic=7.553g/cm3 and Ce2Ni17Si9 structure type.The Rietveld refinement result was Rp= 10.34% and Rwp=13.11%. 4 Crystal structure refinement by Rietveld MethodThe crystal structure of the compound CrFe3NiSn5 has been reinvestigated by X-ray powder diffraction technique and refined by Rietveld profile fitting method. The X-ray powder diffraction data were also provided. The compound CrFe3NiSn5 has a hexagonal space group P6mmm(183) with the lattice parameters a=5.3161 (2) A, c= 4.4256 (2) A, z = 0.6, Dca]c. = 8.011g/cm3 and CoSn structure type. The Rietveld refinement result was Rwp = 0.1433 and Rp = 0.1153 These results have a good agreement with the data obtained from single-crystal X-ray diffraction by Larsson et al.