Improvement of Pinning Characteristics at High Magnetic Fields

Correlated pinning disorder (nanoscale lamellar structure) originating from a chemical composition variation in (Nd,Eu,Gd)Ba₂Cu₃O_y led to an enhancement of flux pinning at high magnetic fields. The irreversibility field was enhanced at 77 K nearly twice, up to 15 T. Since irreversibility field represents the limit for application of high-temperature superconductors at high magnetic fields, the new result significantly extends the field window for bulk superconductors’ application. The most challenging task is to transfer this technology to the second generation of magnetically levitated vehicles (MAGLEV’s), where operation cost reduction is highly demanded. For detailed information see the paper by Muralidhar et al., Physical Review Letters 89, 237001-1-4 (2002). These new results were subject of the patent application submitted to the Japanese Patent Office on 5^th July, 2002.