自组装1-3型外延LaSrFeO_4∶Fe纳米复合薄膜的结构和磁性能研究

Investigation on Structure and Magnetic Properties of Self-assembled 1-3 Type Epitaxial LaSrFeO_4∶ Fe Nanocomposite Film

采用高温固相法制备La0.5Sr0.5FeO3靶材,在高能量,较低的温度条件下利用脉冲激光沉积技术(PLD)在SrTiO3(001)衬底上自助装生长1-3型外延的LaSrFeO4∶Fe(LSFO4∶Fe)纳米复合薄膜。采用X射线衍射仪(XRD)和透射电子显微镜(TEM)表征薄膜的晶体结构和生长取向,磁力显微镜(MFM)观测样品的表面形貌和磁畴结构,超导量子干涉仪(SQUID)磁强计测量薄膜的磁性能。结果表明,α-Fe纳米线的直径大小约为20 nm。在低温10 K时,磁场方向平行和垂直纳米线的矫顽力分别为1645 Oe和923 Oe,饱和磁化强度分别为780 emu/cm3和645 emu/cm3,样品表现出良好的磁各向异性。

Using the La0. 5Sr0. 5FeO3target made by high temperature solid state method. The selfassembled growth 1-3 type epitaxial LaSrFeO4∶ Fe（LSFO4∶ Fe） nanocomposite films were fabricated on SrTiO3（001） substrates by pulsed laser deposition method（PLD） under the high energy and the low temperature. The crystal structure,growth orientation,surface morphology,magnetic domain structure and magnetic properties were characterized by the X-ray diffraction（XRD） and transmission electron microscope（TEM）,by the magnetic force microscopy（MFM）,a superconducting quantum interference device（SQUID） magnetometer. The results indicate that the diameter of α-Fe is about 20 nm. The coercive force of the sample under both field directions of parallel and perpendicular to nanowires are 1645 Oe and 923 Oe, respectively, and the saturation magnetization, showing a large magnetic anisotropy,are 780 emu / cm3and 645 emu / cm3at low temperature of 10 K,respectively.