CAJ | 학술논문

采用原位法粉末装管工艺( in-situ PIT)制备了无定形碳掺杂MgB2/Nb/Cu超导线材并研究了该掺杂对MgB2微观结构及超导电性的影响.复合线材中以Nb作为阻隔层、Cu作为稳定体并采用冷拉拔工艺进行加工.研究了无定形碳掺杂对MgB2相形成、微观结构及超导电性的影响,其中掺杂量分别为MgB2-xCx(x=0.0,0.05,0.08,0.10,0.15).分别采用XRD、SQUID、SEM/EDS及传输电流测试等方法对MgB2/Nb/Cu线材进行分析测试.XRD分析结果显示,700℃热处理后的线材可以获得纯度较高的MgB2超导相;微观结果照片显示无定形碳掺杂后可以获得良好的晶粒连接性;能谱分析表明掺杂物C元素均匀的分布在MgB2基体中;通过四引线法测试了传输临界电流密度Jc,在4.2 K、5T,其Jc值高达1.4×105 A/cm2;在4.2K、10T,其Jc值为3.3×104A/cm2.
채용원위법분말장관공예( in-situ PIT)제비료무정형탄참잡MgB2/Nb/Cu초도선재병연구료해참잡대MgB2미관결구급초도전성적영향.복합선재중이Nb작위조격층、Cu작위은정체병채용랭랍발공예진행가공.연구료무정형탄참잡대MgB2상형성、미관결구급초도전성적영향,기중참잡량분별위MgB2-xCx(x=0.0,0.05,0.08,0.10,0.15).분별채용XRD、SQUID、SEM/EDS급전수전류측시등방법대MgB2/Nb/Cu선재진행분석측시.XRD분석결과현시,700℃열처리후적선재가이획득순도교고적MgB2초도상;미관결과조편현시무정형탄참잡후가이획득량호적정립련접성;능보분석표명참잡물C원소균균적분포재MgB2기체중;통과사인선법측시료전수림계전류밀도Jc,재4.2 K、5T,기Jc치고체1.4×105 A/cm2;재4.2K、10T,기Jc치위3.3×104A/cm2.
The effects of amorphous carbon doping on superconducting properties of MgB2/Nb/Cu wires fabricated by the in-situ powder-in-tube (PIT) method have been investigated.Using Nb as the barrier and Cu as the stabilizer,the MgB2 wires were fabricated by cold drawing.The wires of MgB2-xCx (x =0.0,0.05,0.08,0.10,0.15) have been investigated to realize the effect of amorphous carbon doping on the phase formation,microstructure and superconducting properties.Characterization of MgB2/Nb/Cu wires was carried out using XRD,SQUID,SEM/EDS,and Jc measurements.XRD result shows that the high purity MgB2 phase is acquired after heat-treatment at 700℃.The microstructure observation for wires shows that the MgB2/Nb/Cu wires have better grain connectivity after doping amorphous carbon,and Energy Dispersive X-ray (EDS)analysis confirms the uniform distribution of carbon in the MgB2 superconducting phase.The critical current density (Jc) of wires was measured in different magnetic fields by a standard four probes method,and the transport Jc values as high as 1.4 ×105 A/cm2 (4.2 K,5 T) and 3.3× 104 A/cm2 (4.2 K,10 T) have been achieved.