用背面防护漂浮减薄法制备了扩散Nb_3Sn超导膜的大面积(毫米~2)TEM样品。JEM—200cx电子显微镜对样品的观察表明,这种新的TEM制样方法是成功的。它将有助于直接观察研究与实用Nb_3Sn超导材料相近的扩散薄膜的微结构,探讨磁通线钉扎机理。一、扩散Nb_3Sn薄膜TEM样品的制备扩散Nb_3Sn薄膜是在钼衬底上顺序分层蒸上Nb—Sn—Cu,然后经约800℃扩散形成A15结构的Nb_3Sn层。 A large area (mm ~ 2) TEM sample of diffused Nb_3Sn superconducting films was prepared by back protection floating thinning method. Observation of the samples by the JEM-200cx electron microscope showed that this new TEM sample preparation method was successful. It will be helpful to directly observe and study the microstructure of diffusion films close to practical Nb_3Sn superconducting materials and to explore the pinning mechanism of flux lines. First, the diffusion of Nb_3Sn TEM sample preparation of the film Diffusion Nb_3Sn thin film is sequentially layered on the molybdenum substrate steamed Nb-Sn-Cu, and then diffused by about 800 ℃ to form A15 structure Nb_3Sn layer.