欢迎光临极端条件物理实验室 Ex5研究组

☆高压合成新型量子序物质　☆ 发现"111"型铁基高温超导体　 ☆美国“今日物理”介绍我组发现的"111"型铁基超导

首　　页
(HomePage)

最新研究动态
(Update Research News)

研究成员介绍
(Members)

主要研究方向
（Reasearch Topics Introduction）

主要研究项目
(Reasearch Projects Introduction)

本组发表文章
(Publications List)

实验设备介绍
(Research Facilities Introduction)

国际合作交流
(International Collaboration Exchange)

相关网页链接
(Connections)

首页(Homepage)

As one of the independent thermodynamic parameters apart from those usually studied, such as temperature and composition, pressure has been playing an increasingly important role in condensed matter physics. Pressure can be effective in shortening atomic distance, enhancing orbital overlap, and consequently modifying crystalline structures and tuning interactions. Thus we realize novel high pressure states. It is very well established that each material will usually undergo several phase transitions over the pressure range up to 100 GPa, strongly implying that high pressure could generate plenty of new states of materials based only on the available ambient compounds. Hence high pressure is considered to be a powerful tool to develop novel condensed states. Perovskite-like compounds, especially those of transition metal oxides (TMO) have attracted growing research interest since they manifest such profound physical phenomena, defining some of the current frontiers of condensed matter physics. Perovskite TMO cover the multiple spin–charge–orbital interactions on the base of crystal lattices. Consequently they display physical properties such as superconductivity (including high Tc cuprates), colossal or tunneling magnetoresistance, and novel multiferroic phenomena (e.g., ferroelectricity and ferromagnetism coexisting in the same crystal structure). Deeply understanding those unusual physical phenomena unveils new aspects of the intrinsic physics of TMO. Pressure provides a new dimension for the study of perovskite TMOs. Those strongly correlated electron phenomena will have totally new critical relationships if one investigates the pressure dimension together with the usual temperature and composition parameters. More recently it has been shown that pressure variations stimulate dramatic enhancements of the Tc of HTS, (the record high Tc 160 K was obtained under high pressure in Hg 1223), as well as on the Curie temperature of magnetoelctric coupling compounds. Pressure generally can drive the insulator-metal transition due to the band widening, overlapping effects and the redistribution and transformation of outer shell electrons upon shortening the atomic distance. More important is that high pressure tends to stabilize novel perovskite compounds that otherwise could hardly obtained by conventional means. Not only that the light elements compounds are the traditional focus of high pressure physics. Using high pressure advantages to synthesize and study nitrides, borides, carbides etc. is not only of industrial interest but also important to developing high pressure physics itself since those low Z compounds are theoretically easier to analyze. Nevertheless pressure is a unique and irreplaceable probe to check and develop theoretical model. For instance, pressure can substantially modify the electron correlation and e-p interaction, the spin orientation, giving rise to superconductivity in conventional materials. The delocalization tendency under pressure leads many insulators, semiconductors and molecular crystals to become metals. Pressure more likely will initiate breakthroughs on understanding fundamental scientific problems such as e-e correlation, e-p interaction, charge orbital ordering, etc. High pressure physics as an emerging interdisciplinary science is advancing the state of the art in the physical sciences.

新闻板（Bulletin board）　　　　　　More

中科院物理所极端条件实验室 EX5组版权所有©2004-2011
地址: 中国北京市中关村南三街8号邮编: 100190
Group EX5,Key Laboratory of Extreme Conditions Physics, The Institute of Physics, Chinese Academy of Sciences
Tel: 010-82649163, 82648041 Email: Jin@iphy.ac.cn