Nanostructure and low-dimensional properties of CMR materials

colossal magnetores\（CMR）ferManagement s of perovskite series LaイイD2n-nxイD2CaイD21+nxイD2MnイD2nイD23+1イD2 （n=2，3， and？） have been examined with respected to their electrical and magnetic properties。关于表轴a轴的运输性质的结果与固定载体集中的薄电影样本（x=0.3）已经指示了在各种特征中系统性更改的数量上减少了许多层的结果。这些包括一个在抵抗力中的增加，一个在抵抗力中的减少峰值温度Tc D1 p D1对金属绝缘体过渡的增加，一个在T1 p D1附近的最大MR，以及一个在低温度内的增加。按顺序解释这些特征中的变化与MnO-D12-D1 layers，这是必要的两个C轴转移相互作用，即两个维度自旋流动进入帐户。您的位置：知道173>>对于n=2薄电影，居里温度分解与平面外晶格参数的分解有很大的差异，在磁共振效应的增强中有哪些结果。这些结果是根据晶格不匹配引起的紧张效应的术语来解释的，这些接头是用Perovskite Manganite （n=∞）和Fe （或Co）制造的。这些结果建议这些结果，即隧道电在这些通道中的自旋极化高度依赖于屏障/Fe （或Co）接口的电子结构。

The colossal magnetoresistance (CMR) ferromagnets of perovskite series LaィイD2n-nxィエD2CaィイD21+nxィエD2MnィイD2nィエD2ィイD23+1ィエD2 (n=2,3, and ∞) have been examined with respected to their electrical and magnetic properties. Results on the transport properties of epitaxial a-axis thin film samples with a fixed carrier concentration (x=0.3) have indicated that a reduction in the number of layers results in systematic changes in the various features. These include an increase in resistivity, a decrease in resistivity peak temperature TcィイD1pィエD1 corresponding to the metal-insulator transition, an enhancement of the maximum MR near TcィイD1pィエD1, and an increase in low temperature intrinsic MR. In order to explain the variation in these features with the number of MnOィイD12ィエD1 layers, it is necessary to take both c-axis transfer interaction an two dimensional spin fluctuation into account. These insights are important from the view points of basic understanding of the CMR mechanism and their practical applications.The lattice effect of LaィイD2n-nxィエD2CaィイD21+nxィエD2MnィイD2nィエD2OィイD23n+1ィエD2 have been investigated using thin films (n=2 and ∞) grown on various substrates with the lattice mismatch in the range of -4 〜1%. For the n=2 thin films, the curie temperature decreased very sharply with a decrease of the out-of plane lattice parameters, which results in the enhancement of the MR effect. These results are interpreted in terms of the strain effect induced by the lattice mismatch.The junctions are fabricated using the perovskite manganite (n=∞) and Fe (or Co). These results suggest that the spin polarization of tunneling electrons in these junctions is highly dependent on the electronic structure of the barrier/Fe (or Co) interface.