The Normal State and the Metal-Insulator Transition of High Critical Temperature Superconductors

9501504 Lindenfeld提出的研究解决了这样一个问题，即在何种程度上以及以何种方式，高Tc材料的超导状态的发生和性质受到与绝缘状态的磁序相关的性质的持续存在的影响。 化合物可以通过改变其组成元素的浓度、添加其他元素或施加强磁场而从一种状态转变为另一种状态。 每一条路径都将被遵循，并将测量各种属性，重点是在很宽的温度范围内的磁阻。 在罗格斯大学，将用脉冲激光沉积法制备高Tc材料的取向薄膜。 最初的重点将放在镧锶铜氧化物材料上，该材料已导致生产具有转变温度和其他特性的薄膜，特别是高质量的薄膜。 %拟议的研究调查了所谓“高Tc”材料的低温超导性的发生和性质受到与绝缘形式的磁特性相关的性质的存在的影响的程度和方式。材料。这些化合物可以通过改变其组成元素的浓度，通过添加其他元素，或通过施加强的超导体，从绝缘体变成超导体。 磁 领域的 这一切成功都 方法 将 进行研究，并测量各种特性，重点是在施加磁场的情况下的电阻（磁阻）。将研究在罗格斯大学用脉冲激光沉积技术制备的高Tc化合物薄膜，首先重点是镧锶铜氧化物，这种材料的超导转变温度和 其它性能具有特别高的质量。 ***

9501504 Lindenfeld The proposed research addresses the question to what extent and in what manner the occurrence and properties of the superconducting state of high-Tc materials are influenced by the continuing presence of properties related to the magnetic order of the insulating state. The compounds may be transformed from one state to the other by changes in the concentration of their constituent elements, by the addition of other elements, or by the application of high magnetic fields. Each of these paths will be followed, and a a variety of properties will be measured, with emphasis on the magnetoresistance over a wide range of temperatures. Aligned thin films of high-Tc materials will be prepared at Rutgers by pulsed laser deposition. Initial emphasis will be placed on lanthanum strontium copper oxide material that has led to the production of thin films with transition temperatures and other properties that are of particularly high quality. %%% The proposed research investigates the extent and manner in which the occurrence and properties of the low-temperature superconductivity of so-called "high-Tc" materials are influenced by the presence of properties related to the magnetic characteristics of the insulating form of the material. These compounds may be changed from insulator to superconductor by changes in the concentration of their constituent elements, by the addition of other elements, or by the application of strong magnetic fields. Each of these approaches will be investigated, and a variety of properties will be measured, with emphasis on the electrical resistance in the presence of an applied magnetic field (magnetoresistance). Thin films of high-Tc compounds prepared at Rutgers by pulsed laser deposition techniques will be studied, with initial emphasis on lanthanum strontium copper oxide, a material whose superconducting transition temperature and other propertie s are of particularly high quality. ***