Abstract In this study, we designed a novel magnetic semiconductor Sr2FeMoO6/SrMoO4 with a sharp metal-insulator transition based on the spin-glass freezing and antiferromagnetic transition behavior, which has been confirmed by various magnetic and transport measurements. To investigate the charge transport mechanisms of the sample, the electrical resistivities have been measured over a wide range of temperatures from 400 K down to liquid helium temperatures under different magnetic fields. The typical semiconductor behavior of the sample is observed. The relatively high conduction behavior is blocked below 80 K, and thereafter into the insulator state. The Vogel-Fulcher and the Mott variable-range-hopping (VRH) law are also used to study its conduction features and the relationship between magnetic and electrical properties. The spin-glass like component around the Sr2FeMoO6 crystal is initially observed by TEM and this provides a robust evidence able to verify the results from magnetic measurements. The novel features of the metal-insulator transition shielding external magnetic effects in highly disordered Sr2FeMoO6 double perovskite is dominantly controlled by a new spin-valve-system present in the spin-glass layers. Our insights into the role of the B-site disorder, spin-glass layer around the soft ferromagnetic grains, grain boundaries, and non-magnetic second phase effects demonstrate how the static and dynamic properties of magnetic materials might be tuned by designing the composition with a high B-site cation disordered matrix ferromagnetic material.

中文翻译：

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铁磁半导体 Sr2FeMoO6/SrMoO4 中的自旋阀系统

摘要 在这项研究中，我们设计了一种新型磁性半导体 Sr2FeMoO6/SrMoO4，基于自旋玻璃冻结和反铁磁转变行为，具有尖锐的金属 - 绝缘体转变，这已通过各种磁性和输运测量得到证实。为了研究样品的电荷传输机制，在不同磁场下从 400 K 到液氦温度的广泛温度范围内测量了电阻率。观察到样品的典型半导体行为。相对较高的传导行为在低于 80 K 时被阻止，然后进入绝缘体状态。Vogel-Fulcher 和 Mott 可变范围跳跃 (VRH) 定律也用于研究其传导特性和磁电特性之间的关系。Sr2FeMoO6 晶体周围的自旋玻璃状成分最初是通过 TEM 观察到的，这提供了能够验证磁性测量结果的有力证据。在高度无序的 Sr2FeMoO6 双钙钛矿中，金属-绝缘体过渡屏蔽外部磁效应的新特征主要由自旋玻璃层中存在的新自旋阀系统控制。我们对 B 位无序、软铁磁晶粒周围的自旋玻璃层、晶界和非磁性第二相效应的作用的见解证明了磁性材料的静态和动态特性如何通过设计组成来调整一种高 B 位阳离子无序基质铁磁材料。