Single crystals ofβ–FeSi_(2) have been grown from vapor by employing chemical vapor transport technique and using iodine as transport agent in a closed ampoule.In the experiment,β–FeSi_(2) single crystals with wel...Single crystals ofβ–FeSi_(2) have been grown from vapor by employing chemical vapor transport technique and using iodine as transport agent in a closed ampoule.In the experiment,β–FeSi_(2) single crystals with well-developed faces and edges have been observed on the silicon substrate,but no needlelike ones have been found.The changes in the size and the geometric shape of the growth ampoule and temperature gradient are primary factors which result in the variation on β–FeSi_(2) single crystal morphology.展开更多
Undercooled melt of Ge_(73.7)Ni_(26.3) alloy sample floated on B_(2)O_(3 ) melt was subjected to sputtering-deposition of Ni clusters on cooling to induce solidification.The initial temperature of solidification was 9...Undercooled melt of Ge_(73.7)Ni_(26.3) alloy sample floated on B_(2)O_(3 ) melt was subjected to sputtering-deposition of Ni clusters on cooling to induce solidification.The initial temperature of solidification was 975 K.Its undercoolingΔT was 134 K with respect to the melting temperature of the primary phase Ge.On the cooling curve existed dual recalescences representing the transformation of the primary phase(Ge)and the eutectics(Ge+GeNi)respectively.But for the sample unsputtered,only a single exothermic peak presented on the cooling curve with the initial solidification temperature of 904K and undercooling of 205K.Careful observation of the microstructure proved that the Ge phase primarily formed in the sputtering experiment was now formed together with the formation of the eutectics in the experiment without sputtering.展开更多
The in situ four-point probe resistivity measurement was used as a main method to study the solid/liquid interfacial characteristics in Ag/Sn/Ag trilayers at temperatures ranging from 150 to 305℃.It is found from the...The in situ four-point probe resistivity measurement was used as a main method to study the solid/liquid interfacial characteristics in Ag/Sn/Ag trilayers at temperatures ranging from 150 to 305℃.It is found from the variation of resistivity that three processes take place on annealing:the dissolution of silver atoms,the diffusion of silver atoms,and the formation of Ag3Sn in liquid tin layer.The first one plays the leading role in the variation of resistivity during annealing process.The apparent diffusivity of silver in liquid tin at 305℃ is determined to be 7.3×10^(-17)cm^(2)/s.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.59889102.
文摘Single crystals ofβ–FeSi_(2) have been grown from vapor by employing chemical vapor transport technique and using iodine as transport agent in a closed ampoule.In the experiment,β–FeSi_(2) single crystals with well-developed faces and edges have been observed on the silicon substrate,but no needlelike ones have been found.The changes in the size and the geometric shape of the growth ampoule and temperature gradient are primary factors which result in the variation on β–FeSi_(2) single crystal morphology.
文摘Undercooled melt of Ge_(73.7)Ni_(26.3) alloy sample floated on B_(2)O_(3 ) melt was subjected to sputtering-deposition of Ni clusters on cooling to induce solidification.The initial temperature of solidification was 975 K.Its undercoolingΔT was 134 K with respect to the melting temperature of the primary phase Ge.On the cooling curve existed dual recalescences representing the transformation of the primary phase(Ge)and the eutectics(Ge+GeNi)respectively.But for the sample unsputtered,only a single exothermic peak presented on the cooling curve with the initial solidification temperature of 904K and undercooling of 205K.Careful observation of the microstructure proved that the Ge phase primarily formed in the sputtering experiment was now formed together with the formation of the eutectics in the experiment without sputtering.
文摘The in situ four-point probe resistivity measurement was used as a main method to study the solid/liquid interfacial characteristics in Ag/Sn/Ag trilayers at temperatures ranging from 150 to 305℃.It is found from the variation of resistivity that three processes take place on annealing:the dissolution of silver atoms,the diffusion of silver atoms,and the formation of Ag3Sn in liquid tin layer.The first one plays the leading role in the variation of resistivity during annealing process.The apparent diffusivity of silver in liquid tin at 305℃ is determined to be 7.3×10^(-17)cm^(2)/s.
