Novel Phenomena in Single-Crystal Oxides

技术摘要人们普遍认为，无论谁发现并控制了新材料的优化合成，通常都控制了对它们通常独特性质的研究，并最终成功地将其整合到先进技术中。拟议的研究是建立在我们最近在4d或5d电子基材料的单晶研究上的成功基础上，并强调（1）大块单晶形式的新型过渡金属氧化物的合成和表征以及（2）对新材料的严格搜索。这些材料的新奇是突出了我们最近的发现，如轨道驱动的巨磁阻（CMR），通过避免铁磁状态，和一种新的自旋阀效应，在散装单晶体，一个微妙的量子现象，依赖于精密沉积和纳米级图案化的人工薄膜异质结构的质量和性能是难以控制的。虽然这些发现为理解自旋电子学的基础物理学开辟了新的途径，并充分实现了实际设备的潜力，但这些材料所特有的新物理学（主要由自旋轨道耦合驱动）继续出现，更好地理解这种物理学肯定会导致新的发现。我们寻求的正是这种新的物理学和可能的新发现。技术专长的转移将通过研究生和博士后直接融入正在进行的研究工作来实现，目标是在专业期刊上发表结果。拟议的计划也将成为新成立的多学科先进材料中心的关键推力。该协会将有助于培养跨学科的专业知识，促进合作研究，并产生协同效应，吸引新的学生，他们是推动经济的技术的未来人力资本。凝聚态物理学致力于识别固体和液体的新的基本性质，这些性质在近几十年来产生了大量的尖端技术。人们普遍认为，无论谁发现并控制了新材料的优化合成，通常都控制了对它们通常独特性质的研究，并最终成功地将其整合到先进技术中。不幸的是，美国在材料研究方面的领导地位近年来受到严重侵蚀，原因是拥有新材料合成和表征技能的科学家越来越短缺。目前的局势是一个紧迫的国家挑战，如果不加以解决，最终可能损害我们的经济竞争力。拟议的研究是在我们最近在新材料研究方面取得的成功的基础上，强调大块单晶形式新材料的合成和表征以及对新材料的严格寻找。我们最近的发现突出了这些材料的新奇，例如大块单晶中的新型自旋阀效应，这是一种微妙的量子现象，依赖于人工薄膜异质结构的精确沉积和纳米级图案化，其质量和性能难以控制。自旋阀或更一般的自旋电子（磁电子）材料不仅具有作为磁场传感器和计算机硬盘驱动器读头的技术潜力，而且还对固体中的磁输运理论提出了根本性的挑战。这些是材料物理和工程中研究最深入的现象之一，因为它们对每年1000亿美元的电子行业产生了巨大的潜在影响。这是我们寻求追求的技术潜力和这些材料所带来的智力挑战。技术专长的转移将通过研究生和博士后直接融入正在进行的研究工作来实现，目标是在专业期刊上发表结果。拟议的计划也将构成由NSF EPSCoR RII资助的新成立的多学科先进材料中心的关键推力。 该协会将有助于培养跨学科的专业知识，促进合作研究，并产生协同效应，吸引新的学生，他们是推动经济的技术的未来人力资本。

Technical Abstract It is widely recognized that whoever discovers and controls the optimized synthesis of novel materials generally controls the investigation of their often unique properties and, ultimately, their successful integration into advanced technologies. The proposed research is to build upon our recent success on studies on single crystals of 4d or 5d-electron-based materials and emphasize (1) the synthesis and characterization of novel transition metal oxides in bulk-single-crystal form and (2) a rigorous search for new materials. The novelty of these materials is highlighted by our recent discoveries, such as orbitally-driven colossal magnetoresistance (CMR) attained by avoiding a ferromagnetic state, and a novel spin valve effect in bulk single crystals, a delicate quantum phenomenon that depends upon precision deposition and nanoscale patterning of artificial thin-film heterostructures whose quality and performance are difficult to control. While these discoveries open new avenues for understanding the underlying physics of spintronics, and fully realizing the potential in practical devices, new physics unique to these materials, which are largely driven by spin-orbit coupling, continues to emerge, and better understanding this physics will surely lead to new discoveries. It is this new physics and possible new discoveries we seek to pursue. The transfer of technical expertise will be achieved via direct integration of the graduate students and post-docs into ongoing research efforts with a goal of professional journal publication of results. The proposed program will also constitute a key thrust within the newly established multidisciplinary Center for Advanced Materials. This association will help nurture interdisciplinary expertise that will stimulate collaborative research, and generate synergies that will attract new students who are the future human capital in technologies driving the economy. Non-Technical abstract Condensed matter physics addresses identification of novel, fundamental properties of solids and liquids that have generated a remarkable number of cutting-edge technologies in recent decades. It is widely recognized that whoever discovers and controls the optimized synthesis of novel materials generally controls the investigation of their often unique properties and, ultimately, their successful integration into advanced technologies. Unfortunately, U.S. leadership in materials research has seriously eroded in recent years due to a growing shortage of scientists who possess skills in both the synthesis and characterization of new materials. The current situation presents an urgent national challenge that could ultimately undermine our economic competitiveness if left unaddressed. The proposed research is to build upon our recent success on new materials studies and emphasize the synthesis and characterization of novel materials in bulk-single-crystal form and a rigorous search for new materials. The novelty of these materials is highlighted by our recent discoveries, such as a novel spin valve effect in bulk single crystals, a delicate quantum phenomenon that depends upon precision deposition and nanoscale patterning of artificial thin-film heterostructures whose quality and performance are difficult to control. Spin valves or more generally spintronic (magnetoelectronic) materials not only have technological potential as magnetic field sensors and read-heads for computer hard drives, but also present fundamental challenges to the theory of magnetotransport in solids. These are among the most intensively studied phenomena in materials physics and engineering due to their enormous potential impact on a $100-billion-per-year electronics industry. It is the technological potential and the intellectual challenges these materials present that we seek to pursue. The transfer of technical expertise will be achieved via direct integration of the graduate students and post-docs into ongoing research efforts with a goal of professional journal publication of results. The proposed program will also constitute a key thrust within the newly established multidisciplinary Center for Advanced Materials funded by the NSF EPSCoR RII. This association will help nurture interdisciplinary expertise that will stimulate collaborative research, and generate synergies that will attract new students who are the future human capital in technologies driving the economy.