Investigation On Liquid Structure And Thermodynamics Of Ga Low Melting Point Alloys

Mercury has been used as thermometer for a long time. Because of its great toxicity, it has been prohibit since the United Nations environment programme issued the Minamata convention at On January 19,2013. In order to reduce the damage in the environment and human health damage by mercury, there is a vast potential for future development in thermometer without mercury application. Low melting point Ga alloys have been used as the best choice instead of mercury metal. People tried develop a new kind Ga-In-Sn alloy by adding more elements to it,based on this, in this paper, liquid structures of Ga,Ga-In,Ga-Sn,In-Sn and Ga-In-Sn have been studied by(ab initio molecular dynamics) AIMDFirst, the structures of Ga at different temperature and at the rapid cooling speed are calculated.The study of melting Ga shows that the structure dominated short-range order. Studies has shown that the total nuber of 13XX,14XX bond pairs and Voronoi polyhedra coordintion number of 11,12 ais more than other types. However, there is not a dominant kind of Voronoi polyhedra in Ga melting, and the number of icosahedron is few. For the reason of temperature increasing, there is a devation in the first peak position of g(r) The structure of amorphous Ga is defferent from melting Ga. Amorphous Ga is consist of low coordination number of Voronoi polyhedral and bond pair of 1311,1201,1211.Ga-In, Ga-Sn, In-Sn binary alloy are studied by AIMD. The Mixing enthalpy of the three binary alloy is positive, and AHmix(Ga-ln)<â–³Hmix(In-Sn)<â–³Hmix(Ga-Sn), we find that mixing enthalpy is not the main indicators leading unlike atom aggregation or separation in liquid. The top four bond pair is 1431,1311,1541,1422, respectively, the quantity of 1311 is reduce as In,Sn increasing. The coordination number of Voronoi polyhedral of Ga-centred is mainly 10,11,12, the coordination number of Voronoi polyhedral of In-centren and Sn-centred is mainly 12,13,14..Through the studies of Ga76In14Sn10 at different temperature by AIMD. we find that the top four bond pair is 1431,1311,1422,1541. Under 273K, the quantity of 1431 1541,1551,1441,1661 bond pair bring down as thmperature increase. We find that the quantity of low symmetry bond pair like 1201,1301,1311 is more than the other two alloy in Ga76Ini4Snio liquid. Respectively, self-diffusion coefficient of Ga,In,Sn in Ga76In14Sn10. The coordination number of Voronoi polyhedral of Ga-centred is mainly 10,11,12, The coordination number of Voronoi polyhedral of In-centred is mainly 12,13,14, The coordination number of Voronoi polyhedral of Sn-centred is mainly 12,13.Through the study of Ga76In14Sn9Bi1,Ga76In14Sn9Bi2,Ga76In14Sn9Bi3.5 by DSC. We find a new content alloy, Ga76In14Sn9Bi2 can adapt lager temperature range.