中文摘要：

以硝酸盐为前驱物,利用溶胶-凝胶（sol-gel）法,制备了（Bi1-xLax）2Sr2CaCu2Oδ（x=0,0.1,0.2,0.3,0.4）粉体。通过X射线衍射（XRD）和透射电镜（TEM）,对晶体结构进行了表征;采用SQUID和标准四引线法,对该粉体磁化强度随温度变化（M-T）和电阻随温度变化（R-T）曲线进行了测试,研究了Bi部分被La替代导致Bi系超导体结构和电磁特性的变化。结果表明,随着La掺杂量逐渐增加,晶格常数c未发生变化,而a,b逐渐变大,且沿b轴方向的调制周期减小;样品表现出抗磁性和反铁磁、超导和半导体特性共存、竞争的独特性质。

英文摘要：

Sol-gel method was adopted to prepare the （Bi1-xLax）2Sr2CaCu2Oδ （x=0, 0., 0., 0., 0.4） powders using different nitrates as precursors. Structural characterization was carried out by X-ray diffraction （XRD） and Transmission Electron Microscopy （TEM）. The temperature dependence of resistance R （T） was measured by the standard four-probe technique, and the magnetization M （T） was recorded using a Quantum Design PPMS superconducting quantum interference device （SQUID） magnetometer. The results show that with increasing of La content, the lattice parameters of a and b are decreased, and the modulation period along b axis becomes short. Meanwhile, with the increasing of La content, the character of diamagnetism state and antiferromagnetic state being coexisted and competed is investigated.