材料科学与工程专业个人陈述二.

　　申请专业：材料科学与工程

　　Academic and research background

　　The desire to know more about the nature has motivated me to step into the broad world of science. I have cultivated my great interest in physics, chemistry, biology and a lot of related fields since I was very young. I was armed with strong foundation in physics due to my three years’ time in Tianjin Nankai High School, (one of the most famous high schools in China).

　　In the September of 2000, I entered University of Science and Technology of China and became a member of physics department since then. New environment always brings unexpected difficulties, and great fort has given by me to get adapt to the new life. During the period of hard trying, both my knowledge and my maturity have remarkably grown and I finally got rank above 12 % of 140, with overall GPA 3.5/4.0, and major GPA 3.8/4.0. My hard working finally earned me the Outstanding Student Scholarship in 2003.

　　Besides enhancement of knowledge in physics, I have also accumulated a great deal of knowledge in chemistry and material science. I have got 95/100 in “The Structure and Properties in Solid and Solid State Chemistry” and 87/100 in “Solid State Optics and Spectroscopy”, among the top scores in class. Moreover, I have made fort to improve my ability in mathematics and computer science cautiously.(附加的段)

　　My two years’ research in Structure Research Laboratory of USTC has brought me to a more extensive and practical field of physics. Served as an undergraduate research assistant in Professor Xianhui Chen’s group, I have devoted most of my time to the research and my knowledge in condensed matter physics and its related fields have greatly increased. I have obtained all the basic experimental skills in a very short time and in order to keep with the pace of the latest achievement in my research field, I have spent a large amount of time in reading related journals, such as Appl. Phys. Lett., J. Appl. Phys., Phys. Rev. B, Phys. Rev. Lett., J. Solid State Chem. and so on.

　　At the beginning of 2003, I began my systematical work in exploring the growing method and transport property investigations in hole-doped single crystal BSLCO (Bi2Sr2-xLaxCuO4+y) series and electron-doped NCCO (Nd2-xCexCuO4-y) series. My work was focused on the single crystal preparation and physical property measurement, especially the transport property and magnetic properties. After so many times of attempt in the melting range and descending speed, I successfully grew a great deal of single crystals with high quality. Moreover, I have spent so many days and nights together with my colleagues in lab measuring the resistance of the single crystals under zero field and high field. Due to the high quality of the crystals and our hard work, we finally obtained plenty of meaningful data and by analyzing the normal state property, I have submitted a paper titled “Field-induced log (1/T) diverging resistivity deviation from normal state in superconducting cuprates” to Phys. Rev. Lett. in 2003 as the third author. However, my work was not stopped and with further investigation in the 2D weak localization system, I have submitted another paper to Europhys. Lett. in October 2003 as a co-author.

　　Besides, through the work, I obtained almost all the skills of manipulation of the corresponding instruments from physical preparation to characterization, such as M.Braum Glove-Box system (Germany), MORRIS High Pressure system (Berkeley), Rietveld and Lebail Rinement of crystal structure from XRD pattern, 17 T Ultra-High Magnetic Field system (Oxford Science), AC Assistance Bridge (Liner Research Inc.) sputtering and so on. What’s more, I can skillfully use software, (GSAS, FullProf, CELL PCPDFWIN and etc), to analyze the structure of the material through X-ray diffraction data.

　　Beyond the achievement in research, the happiness I gained from the cooperation with others and the approach of the physics science was greater. Times of failure make me believe that the persistence is the only thing to make people gain their goals and the research work needs active and creative thinking. I often have discussion with other members in my group not only on the current encountered problem but also on the some new ideas for research. During the weekly group meeting, we often exchanged our views on our current research project and I have learned a lot through this communication.

　　Meanwhile, I never give up searching for more extensive and challenging field. Actually, some of my present work is from my own idea. Known the misfit layer of CoO2, I have grown some single crystals of highly ficient thermoelectric materials, such as Bi2Sr2Co2O, Bi2Sr2CoO6+y, Ca3Co4O9....... In order to find the relationship between the misfit structure of CoO2 layer and the high thermoelectricity, magneto-resistance and magneto-power, I have investigated the low-temperature transport, thermal and magnetic properties. By reading a number of related papers, I plan to take further investigation of these materials through their thermoelectric potential and other related measurements.

　　With great interest in nano science, I have paid extra attention to the update technique in synthesizing the nanowires and nanoparticles. Both from the corresponding books in this field and experience of the PhD students in my group, I grasped a number of methods, such as micro-emulsion, hydrothermal method, sol-gel and other soft chemical ways to synthesize the nano scale materials. Under the available condition, I am synthesizing the nano scale superconducting material YBCO and nanowires of magnetic materials, such as La0.5Ba0.5MnO3.

　　More and more do I realize the importance of collaboration, during my exploring of the novel polycrystalline Co1212 and Fe1212. The samples were reported by some group to be superconducting only if it is annealed under the extreme pressure. I have measured the transport property of the crystals and observed some abnormal phase transition of superconductivity. However, because of the limitation of experimental condition, our samples cannot become superconducting. In order to solve the problem, we cooperated with Institute of Physics of China Academic Science to obtain the extreme pressure. Two papers of my work on Co1212 have been submitted to the international journals late this year, and I was the second author. In this case, I realized the cooperation within and without a group is equally important, and sometimes accomplishment is gained under several groups of people. We also have done some work in YBCO thin film transport property, collaborated with professor C. L. Chen of Superconducting Center Texas, U.S.A.

　　In addition, I have also attended some of other sub-group’s research project, such as using sol-gel method to grow Ru1212, NaCoO2 transport property investigation and colossal magneto resistance materials preparation. What’s more, I have also attended the 7th National Superconductivity Conference and National Annual Conference of Physics in 2003. My ken was greatly enlarged by hearing the report of the attendance and my confidence in my research was increased at the same time.

　　Research interest and future plan

　　Material of science and engineering is concerned with the study of structure, properties and applications of materials. During my two years’ research in Structure Research Laboratory, I have accumulated plenty of knowledge in the related area of material science, and meanwhile my ability in doing research is greatly proved. In the past work, I have done quite a lot in synthesis as well as characterization, and I have also deal with different classes of materials, such as electronic, magnetic, superconducting and so on. I believe, aimed with strong foundation of physics, the appropriate area for me to take research work will be more extensive.

　　The area of interest is just as following:

　　1. I have read a lot of corresponding papers in magnetic recording research, and I have great interest in this kind of materials. I believe research in this area is important both for basic studies of the fects of dimensionality and interactions, and for the future of magnetic recording. Hence, I wish to do some work in synthesis and processing of this kind of materials.

　　2. Because nano materials, such as carbon nanotubes, nano particles, quantum dots, nano-porous structures, and nano-electronics device materials, are the essential part of the current and future nano-based technologies. I hope very much to continue my future research work in this area.

　　3. Moreover, I am also interested in the structural material, such as advanced engineering materials, which characters may be changed responding to the different mechanic condition. So I think I also hope to do the related research in analysis of materials property.

　　My future plan is to pursue my PhD degree in material science and engineering. In fact, though the technology is developing at a tremendous speed, there is still a lot of progress remaining to be made. For instance, nanoscale devices, either assembled lithographically or chemically, will have a high probability of failure. Therore, any architecture built from large numbers of nano scale devices will necessarily contain a large number of dects, which fluctuate on time scales comparable to the computation cycle. Furthermore, deeper insight should be given into the constraints imposed by nano-devices, especially carbon nanotube-based devices, by modeling the devices and corresponding architectures. Such a framework can contribute towards building more powerful nano-probes, nano-computer and ficient power fuel-cells.

　　Why I Choose UCSD

　　UCSD is world famous for its outstanding faculty and reputation. Though the economic condition in California is not so satisfying at the moment, I believe it will not impede the future development of UCSD.

　　The Materials Science and Engineering Program at UCSD aims to provide fundamental knowledge for understanding of materials with the objective of predicting, modifying, and tailoring the properties of materials to yield, at the technology level, enhanced material performance. Also, I was greatly impressed by the great collaboration of different departments, which makes the Materials Science department more competitive and attractive. With so many outstanding professors and so broad research areas, I was convinced that the Material Science and Engineering Department is always the best choice for me to pursue my PhD degree.