RUI: Physics of 2D and 3D Perovskites

9705155 Oseroff我们将对2D和3D钙钛矿进行系统研究。第一部分是La_2NiO_4和La_2CuO_4掺杂的研究，主要用电子自旋共振(ESR)方法进行。Li+将一个洞带入平面，这个洞似乎是局部化的。这项工作提供了比较具有面内孔洞的系统和具有通过面外替换引入的移动孔洞的系统的可能性。第二部分与钙钛矿型锰酸盐R_(1-x)B_xMnO_3(R=La，Pr等，B=Ca，Sr等)的巨大磁阻响应有关。我们将进行：a)T_c和H_T之间的ESR研究；b)从20 nm到100 nm的Lal-xCaxMnO_3+小颗粒的研究。C)对稀释体系的测量，如LaScO_3+：Mn。这项研究应该会为这些系统的基本物理提供新的见解，并有望导致更好的理论模型。非技术摘要1986年，Bednorz和Muller发现掺杂La2CuO4成为高温超导体HTS。从那时起，大量的实验学家和理论家为了解高温超导的起源做出了巨大的努力。尽管作出了巨大努力，但仍未达成共识。我们将对已经报道的数据进行系统分析。结合几个精心挑选的实验，这应该有助于我们理解这些迷人的、可能有用的材料的基本物理。接下来，我们将对类似的掺杂LaMnO_3家族的成员进行测量。这些系统与HTS材料具有共同的重要特征，通过成为未来的磁性传感器，它们具有提高存储密度的巨大潜力。***

9705155 Oseroff We will perform a systematic research on 2D and 3D perovskites. The first part is a study of La2NiO4 and La2CuO4 doped with Sr and Li, which will be carried out mainly by Electron Spin Resonance, ESR. Li+ brings a hole into the plane and this hole appears to be localized. This work offers the possibility of comparing systems with in- plane holes to those with mobile ones introduced by out-of- plane substitutions. The second part is connected with the huge magnetoresistive response found in the perovskite manganate R1-xBxMnO3 with (R=La, Pr, etc. and B = Ca, Sr, etc.). We will perform: a) An ESR study between Tc and high T. b) Research on small grain size particles of Lal-xCaxMnO3+ from 20 nm to 100 nm. c) Measurements on diluted systems, such as LaScO3+: Mn. This research should provide new insight into the underlying physics of these systems and hopefully lead to better theoretical models. %%% Non-Technical abstract In 1986 Bednorz and Muller discovered that doped La2CuO4 becomes a High Temperature Superconductor, HTS. Since then an enormous effort has been made by a large number of experimentalists and theoreticians to understand the origin of high-temperature superconductivity. In spite of the tremendous efforts made, no consensus has been reached. We are going to carry out a systematic analysis of the data already reported. This, in conjuction with a few well selected experiments, should help us understand the underlying physics of these fascinating and possibly useful materials. We will follow this by carrying out measurements on members of a similar family, doped LaMnO3. These systems share important features with the HTS materials, and they have a great potential for boosting storage density by becoming the magnetic sensors of the future. ***