摘　要 近年来，人们对过渡金属氧化物的界面二维电子气（2DEG）体系进行了广泛又细致的研究，其中最为典型的是（001）LaAlO3/SrTiO3（LAO/STO）界面，它具有可调控的载流子浓度和高迁移率等优点，并在界面处观测到铁磁性、超导性、铁磁超导共存、Rashba自旋轨道耦合等一系列新奇的物理现象。基于这些丰富的性质，课题组们在（001）LaAlO3/SrTiO3界面二维电子气上进行了一系列有关自旋极化的输运测量与研究，这为（001）LaAlO3/SrTiO3界面二维电子气体系提供了更为深远的研究目标和机遇，同时也为自旋电子学器件的发展提供了更好的研究平台。不过当前诸多目光仅仅聚焦于SrTiO3基片上，由于掺杂不同元素的基片可能会使二维电子气的性质发生改变，所以本论文尝试在wt0.05%的Fe:STO基片上制备Co/LaAlO3/Fe:SrTiO3异质结并对其进行了自旋极化输运性质探索，取得了以下研究成果： （1）成功制备了高质量的(001)LaAlO3/Fe:SrTiO3异质结 利用脉冲激光沉积方法在掺铁浓度为0.05%的（001）Fe:SrTiO3 基片上生长了取向为（001）的高质量LaAlO3薄膜。通过原子力显微镜（AFM）和X射线衍射（XRD）表征结果，已显示出Fe:SrTiO3基片上良好的外延了准二维和原子量级平整度的LaAlO3薄膜。同时测量样品的基本输运性质，包括界面电阻随温度的变化曲线，Hall效应等等。 （2）制备了Co/LaAlO3/Fe:SrTiO3异质结 利用磁控溅射技术，在LaAlO3/Fe:SrTiO3异质结上透过大小为400um×500um的掩膜版，溅射铁磁性金属Co和非磁性金属Au并以此作电极，利用台阶仪对Co进行了厚度测量，并对此异质结构进行基本输运的测量。 （3）利用PPMS研究了Co/LaAlO3/Fe:SrTiO3异质结的自旋极化输运性质 通过PPMS研究并测量异质结的自旋极化输运特性。结果表明，施加面内磁场时出现正磁阻现象；当施加面外磁场时，出现负磁阻现象。随着温度的不断升高，正磁阻和负磁阻都呈现这不断减小的趋势，我们认为有可能是因为Fe:SrTiO3基片存在大量的氧空位导致的。

In recent years, extensive and meticulous research has been carried out on the interfacial two-dimensional electron gas (2DEG) system of transition metal oxides, the most typical of controllable interface is the (001) LaAlO3/SrTiO3 (LAO/STO) interface. The carrier concentration and high mobility are excellent, and a series of novel physical phenomena such as ferromagnetism, superconductivity, ferromagnetic superconductivity coexistence and Rashba spin-orbit coupling are observed at the interface. Based on these rich properties, the research team conducted a series of transport measurements and studies on spin polarization on the (001)LaAlO3/SrTiO3 interface two-dimensional electron gas. The system of the (001)LaAlO3/SrTiO3 interface two-dimensional electron gas provides far-reaching research goals and opportunities, and also provides a better research platform for the development of spintronic devices.However, many current eyes only focus on the SrTiO3 substrate. Since the substrate doped with different elements may change the properties of the two-dimensional electron gas, this thesis attempts to prepare Co/LaAlO3/Fe:SrTiO3 heterojunction on a wt0.05% Fe:SrTiO3 substrate.and its spin-polarized transport properties were explored, and the following research results were obtained: (1)High quality （001）LaAlO3/Fe:SrTiO3 heterojunction has been successfully prepared. A high-quality LaAlO3 film oriented at (001) was grown on a (001)Fe:SrTiO3 substrate doped with iron at a concentration of 0.05% by pulsed laser deposition. The results of atomic force microscopy (AFM) and X-ray diffraction (XRD) show that the LaAlO3 film with good epitaxial and atomic order flatness on the Fe:SrTiO3 substrate has been well exhibited. Simultaneously measure the basic transport properties of the sample, including the curve of interface resistance with temperature, Hall effect and so on. (2)Co/LaAlO3/Fe:SrTiO3 heterojunction has been prepared. Using magnetron sputtering technology, the thickness of Co and Au was measured by step apparatus, and the basic transport of the heterojunction is measured by using the magnetron sputtering technology, which sputtered the ferromagnetic metal Co and non-magnetic metal Au on the LaAlO3/Fe:SrTiO3 heterojunction through a 400 um ×500 um mask. (3)The electrical properties of Co/LaAlO3/Fe:SrTiO3 heterogeneous tunnel junction are studied by using PPMS. The spin-polarized transport properties of heterojunction were investigated and measured by PPMS. The results show that the positive magnetoresistance occurs when an in-plane magnetic field is applied, and the negative magnetoresistance occurs when an out-of-plane magnetic field is applied. As the temperature increases, both positive and negative magnetoresistance show a decreasing trend. We believe that it is possible that there is a large amount of oxygen vacancies in the Fe:SrTiO3 substrate.