Self-assembled, rare earth tantalate pyrochlore nanoparticles for superior flux pinning in YBa2Cu3O7−δ films

• Published in: Superconductor science & technology 2009-02, Vol.22 (2), p.022001-022001 (5)
• Main Authors: Harrington, S A, Durrell, J H, Maiorov, B, Wang, H, Wimbush, S C, Kursumovic, A, Lee, J H, MacManus-Driscoll, J L
• Format: Article
• Language: English
• ISSN: 0953-2048; 1361-6668
• DOI: 10.1088/0953-2048/22/2/022001

Addition of pyrochlore rare earth tantalate phases, RE3TaO7 (RTO, where RE = rare earth, Er, Gd and Yb) to YBa2Cu3O7-delta (YBCO) is shown to vastly improve pinning, without being detrimental to the superconducting transition temperature. The closely lattice matched to RTO phase provides a lower interfacial energy with YBCO than BaZrO3 (BZO) and produces very fine (~5 nm) particles with high linearity in their self-assembly along c. Critical current densities of 0.8,0.38 MA cm-2 at 1 and 3 T (for fields) parallel to the c axis were recorded at 77 K in 0.5-1.0 mum thick films and a transition temperature of 92 K was observed even in the highest level doped sample (8 mol%).