Sr掺杂Ca₃Co₄O_9+δ基质材料的制备与磁性研究

Preparation and Study on Magnetic Properties of Sr-Doped Ca₃Co₄O_9+δ

摘要: 本文采用溶胶–凝胶与热压烧结相结合法制备了Ca_3−xSr_xCo₄O_9+δ(x = 0，0.05，0.15和0.25)块体。利用X射线衍射(XRD)和扫描电镜(SEM)，对材料的物相和形貌进行分析。XRD结果显示随着Sr掺杂浓度的增加，衍射峰向小角度方向偏移，表明Sr已掺杂进入Ca₃Co₄O_9+δ基材料晶格中；通过分析材料的SEM，发现材料的晶粒呈层状结构并且尺寸均匀。通过振动样品强磁计(VSM)分析样品磁性，结果为样品的磁性随Sr的掺杂而提高。

Abstract: Ca_3−xSr_xCo₄O_9+δ (x = 0, 0.05, 0.15 and 0.25) were synthesized by sol-gel and hot-press method. The X-ray plane diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the crystal structure and morphology. The result of XRD shows that the diffraction peak moves to the small angle side with the increase of Sr doping concentration. It also indicates that Sr has doped into the lattice of the Ca₃Co₄O_9+δ based materials. As shown in the SEM images, the material exhibits the lamellar-like structure. Moreover, the particle size distribution is uniform. The magnetic properties of the materials were characterized by the viberating sample magnetometer (VSM), which demonstrated that the magnetic properties of the materials were enhanced with the increase of Sr doping.