TY - JOUR
T1 - Preparation of 94 K-superconducting NdBa2Cu3O7-δ without post-anneal in oxygen
AU - Fujihara, S.
AU - Yoshida, N.
AU - Kimura, T.
PY - 1997/3/1
Y1 - 1997/3/1
N2 - The preparation of the polycrystalline NdBa2Cu3O7-δ superconductor using Ba2Cu3O5+x as a precursor has been studied. Ba2Cu3O5+x was prepared by the sol-gel process using metal acetates as starting materials, tartaric acid as an chelating reagent and water as solvent. The gel was heated at 780°C for 60 h in O2 to form the Ba2Cu3O5+x. precursor. The value of x in Ba2Cu3O5+x was determined to be 0.5; that is, copper was in a highly oxidized state over +2. NdBa2Cu3O7-δ was obtained by the solid-state reaction between Nd2O3 and Ba2Cu3O5+x heated at 900°C for 20 h in N2. Although the sample did not undergo post-anneal in oxygen, it showed good superconducting properties; Tc of 94 K and the intragranular Jc of 3.7 × 105 A/cm2 under a field of 50 kOe at 20 K. The advantage of using Ba2Cu3O5+x is considered to be its sufficient amount of oxygen as well as prevention of the Nd3+/Ba2+ substitution.
AB - The preparation of the polycrystalline NdBa2Cu3O7-δ superconductor using Ba2Cu3O5+x as a precursor has been studied. Ba2Cu3O5+x was prepared by the sol-gel process using metal acetates as starting materials, tartaric acid as an chelating reagent and water as solvent. The gel was heated at 780°C for 60 h in O2 to form the Ba2Cu3O5+x. precursor. The value of x in Ba2Cu3O5+x was determined to be 0.5; that is, copper was in a highly oxidized state over +2. NdBa2Cu3O7-δ was obtained by the solid-state reaction between Nd2O3 and Ba2Cu3O5+x heated at 900°C for 20 h in N2. Although the sample did not undergo post-anneal in oxygen, it showed good superconducting properties; Tc of 94 K and the intragranular Jc of 3.7 × 105 A/cm2 under a field of 50 kOe at 20 K. The advantage of using Ba2Cu3O5+x is considered to be its sufficient amount of oxygen as well as prevention of the Nd3+/Ba2+ substitution.
KW - BaCuO
KW - Critical current density
KW - Magnetization
KW - NdBaCuO
KW - Sol-gel
UR - http://www.scopus.com/inward/record.url?scp=0031096727&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031096727&partnerID=8YFLogxK
U2 - 10.1016/S0921-4534(97)00007-5
DO - 10.1016/S0921-4534(97)00007-5
M3 - Article
AN - SCOPUS:0031096727
VL - 276
SP - 69
EP - 74
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - 1-2
ER -