Conductivity, magnetoresistance, and the Hall effect in granular Fe/SiO2 films
Conductivity, magnetoresistance, and the Hall effect in granular Fe/SiO2 films
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DOI：
10.1134/1.1130891
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发表时间：
1999-06-01
影响因子：
0.6
通讯作者：
Sedova, MA
中科院分区：
文献类型：
--
作者：
Aronzon, BA;Kovalev, DY;Sedova, MA
我们研究了颗粒状Fe/SiO_2薄膜的电导、磁电阻和霍尔效应，铁颗粒的尺寸在40埃左右，其体积分数x在0.3-0.7之间。对于x < 0.6，已经建立了传导激活机制。在过渡的绝缘体侧，我们观察到一个巨大的负磁阻，急剧下降的金属体积分数减少。对于x < 0.4，我们观察到预磁化样品的大的正磁阻，显示在类似于100 Oe的磁场中，并且以大的响应时间为特征。在电介质样品中的霍尔效应的场依赖性，在金属样品中，与它们的磁化强度相关。我们发现霍尔电阻与纵向电阻的平方根成正比，这不能用已知的反常霍尔效应模型来解释。(C)1999年美国物理学会。[S1063-7834（99）00406-2]。
We have investigated the conductance, magnetoresistance, and Hall effect in granular Fe/SiO2 films with size of the iron grains around 40 Angstrom, whose volume fraction x lies in the range 0.3-0.7. The conduction activation regime has been established for x < 0.6. On the insulator side of the transition we observed a giant negative magnetoresistance, falling off sharply as the metal volume fraction decreases. For x < 0.4 we observed a large positive magnetoresistance of premagnetized samples, showing up in fields similar to 100 Oe and characterized by large response times. The field dependence of the Hall effect in the dielectric samples, as in the metallic samples, correlates with their magnetization. We found that the Hall resistance is proportional to the square root of the longitudinal resistance, which cannot be explained by known models of the anomalous Hall effect. (C) 1999 American Institute of Physics. [S1063-7834(99)00406-2].