Simulation Study Of Microstructure Transition Of Electronic Material Ga During Rapid Cooling Solidifications

In this paper, the significance of electronic material in electronic information industry has been summarized. The relations of electronic material structure composition and electronic characteristics have been also described, and the important of structural analysis has been pointed out. As a kind of important electronic material,electronic material Ga is widely used in the semiconductor industry. A computer simulation tracing study for the rapid cooling process of electronic material Ga system consisting of 1000 atoms has been performed by using molecular dynamics mothod. Adopting the Honeycutt-Andersen (HA) bond-type index method and the cluster-type index method, the bond-types and the basic cluster configurations formed by metal Ga atoms have been analyzed. We find when cooling rate is fast, with the temperature decresing, the number of icosahedron and the relative numbers of 1551, 1541 bond types related to the icosahedron decrease obviously; the total number of 1421, 1422 bond types related to the cubic (fcc, bcc) and hcp structures increase obviously; and the total number of 1311, 1301 and 1201 bond types related to the rhombohedral structure increase remarkably, and gradually play a dominant role. Finally, an amorphous structure is formed mainly with rhombohedral structures mixed up with clusters of cubic (fcc, bcc) and hcp structures. In order to further grasp the microstructures of Ga, we study the system cooling with different rates. It has been found that the amorphous are formed with cooling rate 1.0×1014,1.0×1013,1.0×1012K/s, while, the crystal structures are formed with cooling rate 1.0×1011 K/s. With the decreasing of temperature, the liquid and amorphous structures have almost disappeared. It is proved that face centered cubic crystal (f.c.c) structure configuration already becomes superior to the other systems, and it has distinct crystal characteristics. The last, we found with the same cooling rate, the characteristic of solidification of Ga can also be affected by different initial conditions. The crystal structures are formed with initial 20000 time steps; while, the amorphous are formed with initial 30000 and 40000 time steps.The results will give us a new way to understand the microstructure transitions of electronic material from liquid to solid states. In addition, the results will have important practical significance to choose cooling rates correctly in order to obtain electronic material with excellent properties.