Electrical transport properties in Fe-Cr nanocluster-assembled granular films
Electrical transport properties in Fe-Cr nanocluster-assembled granular films
复制标题
Fe-Cr 纳米团簇组装颗粒薄膜的电传输特性
DOI：
10.1016/j.jmmm.2017.04.076
复制
发表时间：
2017
影响因子：
2.7
通讯作者：
Peng D.L.
中科院分区：
文献类型：
--
作者：
Wang X.Z.;Wang L.S.;Zhang Q.F.;Liu X.;Xie J.;Su A.M.;Zheng H.F.;Peng D.L.
摘要利用等离子体-气体冷凝团簇沉积系统制备了Cr原子分数（x）为0 ~ 100的Fe 100-xCrx纳米团簇组装颗粒膜。TEM表征表明，均匀的Fe团簇表面包覆了一层Cr，形成了Fe-Cr核壳结构。然后，在真空环境中，随着沉积时间的增加，所制备的Fe 100-x Cr x纳米团簇随机组装成颗粒状薄膜。由于界面电阻与Cr层分流效应的竞争，Fe 100-xCrx纳米团簇组装颗粒膜的室温电阻率随着Cr原子分数（x）的增加先增大后减小，在x= 26 at.%时出现最大值2× 104 μΩ cm。系统地研究了Fe 100-xCrx纳米团簇组装颗粒膜的纵向电阻率（ρ xx）、磁电阻（MR）效应和反常霍尔效应（AHE）随温度的变化。当x从0增加到100时，所有样品的ρ xx随测量温度的升高先减小后增大。ρ xx对温度的依赖性可以通过涨落诱导隧穿（FIT）导电过程和温度相关散射效应的机制来解决。结果表明，Fe 100-xCrx纳米团簇组装颗粒膜的反常霍尔效应（AHE）没有明显的标度关系.然而，扣除隧道效应的贡献后，标度关系是明确的。此外，Fe 100-xCrx纳米团簇组装颗粒膜表现出较小的负磁阻效应，且随着x的增加而减小.详细的物理机制的电输运性质在这些Fe 100-x Cr x纳米团簇组装颗粒膜进行了研究。
Abstract The Fe 100-x Cr x nanocluster-assembled granular films with Cr atomic fraction (x) ranging from 0 to 100 were fabricated by using a plasma-gas-condensation cluster deposition system. The TEM characterization revealed that the uniform Fe clusters were coated with a Cr layer to form a Fe-Cr core-shell structure. Then, the as-prepared Fe 100-x Cr x nanoclusters were randomly assembled into a granular film in vacuum environments with increasing the deposition time. Because of the competition between interfacial resistance and shunting effect of Cr layer, the room temperature resistivity of the Fe 100-x Cr x nanocluster-assembled granular films first increased and then decreased with increasing the Cr atomic fraction (x), and revealed a maximum of 2× 10 4 μΩ cm at x= 26 at.%. The temperature-dependent longitudinal resistivity (ρ xx), magnetoresistance (MR) effect and anomalous Hall effect (AHE) of these Fe 100-x Cr x nanocluster-assembled granular films were also studied systematically. As the x increased from 0 to 100, the ρ xx of all samples firstly decreased and then increased with increasing the measuring temperature. The dependence of ρ xx on temperature could be well addressed by a mechanism incorporated for the fluctuation-induced-tunneling (FIT) conduction process and temperature-dependent scattering effect. It was found that the anomalous Hall effect (AHE) had no legible scaling relation in Fe 100-x Cr x nanocluster-assembled granular films. However, after deducting the contribution of tunneling effect, the scaling relation was unambiguous. Additionally, the Fe 100-x Cr x nanocluster-assembled granular films revealed a small negative magnetoresistance (MR), which decreased with the increase of x. The detailed physical mechanism of the electrical transport properties in these Fe 100-x Cr x nanocluster-assembled granular films was also studied.