德国Bayerisches大学Bayerisches Geoinstitut研究所博士招生信息

       德国Bayerisches大学Bayerisches Geoinstitut研究所的Tommo Katsura教授计划招生一名有志于高温高压实验地球科学研究的博士生，该博士培养计划得到德国研究基金（DFG）的资助。主要的研究课题为：Si在含铁或不含铁wadsleyite单晶中的自扩散系数及其与温度与水含量的关系。学制为三年制，2014年10月份入学。

       德国拜伊罗特大学高压实验中心（Bayerisches Geoinstitut）位于拜伊罗特城的拜伊罗特大学校园内。 这个研究所主要从事高温高压方向的研究，在世界高压领域享有很高的声誉，在近15年已经有40余篇文章发表在Nature、Science等著名期刊上。Katsura教授在电导率测量、地幔矿物流变学、地幔矿物相变、多面砧压机高压技术、多面砧压机同步辐射研究、高压矿物的单晶生长等诸多方向有很深的造诣。目前已指导的学生在Nature等国际顶级科研杂志发表了多篇研究论文。有兴趣的请参看简介：http://www.bgi.uni-bayreuth.de

       候选者要求：（1）具有硕士学位或与硕士水平相当；（2）具有基本的固体地球科学、物理学、化学、数学知识背景。注：不要求具有高温高压实验技能，学习工作的语言为英语，德语方面也没有要求。招生工作一直持续到招满为止。

       报考者请准备以下材料：（1）“europass”格式的个人简历；（2）简练的个人硕士论文总结；（3）所获学位证书、各种获奖证书、成绩单复印件；（4）一封评价自己及个人研究兴趣的简介信。个人材料请通过Tomo.Katsura@unibayreuth.de

信箱直接寄往Katsura教授。若有相关咨询问题的，请与地质过程与矿产资源国家重点实验室的郭新转老师联系：gxzhuan@gmail.com

Prof. Dr. Tomoo Katsura


Professor of Structure and Dynamics of Earth Materials

Director of Bayerisches Geoinstitut, University of Bayreuth

95440 Bayreuth, GERMANY


Tel: +49(0)921 553791,


Fax: +49(0)921 553769


Email: Tomo.Katsura@unibayreuth.de

研究内容简介：

Title:
Measurement of Si self-diffusion coefficients of wadsleyite as a function of temperature and water content

Project description:
Dynamic motion in the mantle accounts for a wide variety of geological and geophysical phenomena. Understanding dynamic mantle flow is therefore essential for solid-state geophysics. Rock deformation experiments have shown a large decrease in the creep strength of mantle minerals by hydration. However, deformation experiments are technically difficult, and the inherent lack of control on key parameters makes interpretation of experimental results problematic. Measurements of Si self-diffusion coefficients have the potential to provide an essential and independent source of information about the high-temperature rheology of minerals, because the slow high-temperature creep of silicate minerals should be controlled by Si self-diffusion. We have studied the effect of water on the Si self-diffusion of forsterite [Fei et al., 2013]. This study suggests that the effect of water on mantle rheology is much smaller than previously considered; although the water content exponent on the olivine rheology was considered to be 1.2, it is actually only 0.3. This striking conclusion should be extended by examining other important mantle minerals. Wadsleyite is a dominant constituent mineral in the mantle transition zone. In this study, we will measure Si self-diffusion coefficient of both Fe-free and Fe-bearing wadsleyite with water contents from<1 to 1000 ppm at temperatures of 1400 and 1600 k, determining them as a function of temperature and water content. in this kind of study, use of single crystal samples is essential for reliable measurement. we will synthesize wadsleyite single crystals based on the techniques developed in our previous study [Shatskiy et al., 2009]. The measurement of Si self-diffusion coefficients of wadsleyite will be conducted by following those in our previous study for forsterite [Fei et al., 2012; 2013]. For the iron-bearing samples, pre- annealing and diffusion annealing will be conducted under constant oxygen fugacity buffered by Mo + MoO2. Based on the results of this project, we will examine and improve our understanding of the effects of water on mantle rheology. This work will provide important insights required to properly understand the dynamic behavior of the mantle.

References:

Fei, H. Z., C. Hegoda, D. Yamazaki, M. Wiedenbeck, H. Yurimoto, S. Shcheka, and T. Katsura (2012), High silicon self-diffusion coefficient in dry forsterite, Earth Planet. Sci. Lett., 345, 95-103.


Fei, H., M. Wiedenbeck, D. Yamazaki & T. Katsura (2013), Small effect of water on upper-mantle rheology based on silicon self-diffusion coefficients, Nature, 498(7453), 213-215.
Shatskiy, A., K. D. Litasov, T. Matsuzaki, K. Shinoda, D. Yamazaki, A. Yoneda, E.

Ito, and T. Katsura (2009), Single crystal growth of wadsleyite, Am. Miner., 94(8-9), 1130-1136.