稀土掺杂锰氧化物庞磁电阻效应

过去十多年来，具有庞磁电阻效应的稀土掺杂锰氧化物成为了凝聚态物理研究的重要领域。锰氧化物的载流子自旋极化率高，且在居里温度附近表现出很大的磁电阻效应，因此在自旋电子学中有潜在的应用前景。另一方面，锰氧化物是典型的强关联电子体系，它对目前有关强关联体系的认识提出了很大挑战。本文综述了锰氧化物的各种性质及其物理原因。全文首先概述了锰氧化物的庞磁电阻效应及其晶格和电子结构，简单介绍了其他一些庞磁电阻材料；随后综述了锰氧化物的电荷／轨道有序相及其输运性质；在第四部分简单介绍了锰氧化物中庞磁电阻效应的机制；最后讨论了锰氧化物的一些可能的应用，如低场磁电阻效应、磁隧道结、磁p-n结以及全钙钛矿的场效应管和自旋极化电子注入装置等。

COLOSSAL MAGETORESISTIVE MANGANITES

Colossal magnetoresistive materials such as rare_earth manganites have been receiving special attentions in the community of condensed matter physics. They are expected to find a number of potential applications in spintronics for their high_spin polarity and colossal magnetoresistive (CMR) effect around the Curie temperature. The significance of manganites and related CMR effect in forging our comprehensive understanding of strongly correlated electron systems can't be emphasized more. In this article, we present a comprehensive review on the electronic structure, transport and magnetic properties of manganites and underlying physics. First, we give an introduction to the crystal and electronic structures and colossal magnetoresistive effect of manganites; then describe the curious charge_ordered and orbital_orderd states as well as transport properties of maganites. Subsequently, we highlight the physics underlying the colossal magntoresistance effect, in particular the physics of electronic phase separation. Finally, we discusse several issues related to the potential applications of manganites in microelectronics and spintronics, such as low_field magnatoresistance, tunneling magnetoresistance, magnetic p_n junctions, field_effect_transistors based on manganites and spin_injection prototypes.