Mesoscopic Phase Modulations in Complex Materials

研究化学上复杂的氧化物和其他材料，不仅是因为它们所表现出的有趣的物理现象，而且是为了将它们结合在器件中以实现所需的功能。这种具有各种耦合物理自由度的功能复杂材料已被证明有利于介观相位调制。科学地理解这些调制与宏观物理性质之间的相互关系对于控制复杂材料的工艺功能至关重要。这个项目的重点是各种新系统的合成和协作实验，以研究它们的物理性质。具体的主题包括受挫反铁磁体中自旋团簇的纳米级自组织，锰中的多尺度铁磁畴结构以及混合价氧化物中载流子的动态重排序。本文还将研究铋超导体中电荷密度波和涡旋与铁电弛豫器的物理特性之间可能存在的关联。拟议的活动将通过雇用（代表性不足的）高中生（例如通过新泽西州的自由科学中心）、本科生、研究生和博士后，进一步加强研究在各级教育中的作用。本课题的研究成果将用于丰富研究生材料物理课程。在新材料中存在许多具有不同电子或磁性结构的小介观区域，可能导致完全不同的宏观性质。提出的研究旨在了解这些介观相调制与几种材料宏观物理性质之间的相互关系。这种理解是决定性的因素，它将使复杂材料在新兴技术中发挥所需的功能成为可能。该项目涉及综合和表征工作，利用各种技术和技能，通过建立一个合作的机构间和国际研究团队。建议的研究将通过雇用高中，本科生和研究生进一步加强研究在各级教育中的作用。例如，高中生将通过科学合作伙伴计划（由新泽西州自由科学中心组织）和为纽瓦克地区未被充分代表的高中生举办的夏季研讨会参与拟议的研究。

Chemically complex oxides and other materials are being investigated not only for the interesting physical phenomena they exhibit but also with a view to incorporating them in devices to perform desired functions. Such functional, complex materials with various coupled physical degrees of freedom have proven to be conducive to mesoscopic phase modulations. Scientific understanding of the interrelationship between these modulations and macroscopic physical properties is of prime importance for controlling the technological functionality of complex materials. This project is focused on the synthesis of a variety of novel systems and collaborative experiments for the study of their physical properties. The specific topics include the nanoscale self-organization of spin clusters in frustrated antiferromagnets, multiscale ferromagnetic domain structures in manganites and the dynamic reordering of charge carriers in mixed-valent oxides. The possible correlation of charge density waves and vortices in Bi superconductors and the physics of ferroelectric relaxors will be also studied. The proposed activities will further strengthen the role of research at all levels of education by employing (underrepresented) high school students (through, e.g., the Liberty Science Center, New Jersey), undergraduate students, graduate students as well as postdocs. Research results from this project will be used for enriching graduate materials physics course. The presence of many small, mesocopic regions of distinct electronic or magnetic structures in novel materials may lead to entirely different macroscopic properties. The proposed research is aimed at the understanding of the interrelationship between these mesoscopic phase modulations and macroscopic physical properties in several materials. This understanding can be the decisive factor that will make the use of complex materials to perform desired functions in emerging technologies possible. The project involves synthesis and characterization efforts using a variety of techniques and skills available through an established, collaborative inter-institutional and international team of researchers. The proposed study will further strengthen the role of research at all levels of education by employing high school, undergraduate, and graduate students. For example, high school students will be involved in the proposed research through the Partners in Science program (organized by the Liberty Science Center, NJ) and a summer workshop for the underrepresented high school students in the Newark area.