Excellent Critical Current Properties of Dilute Sr-Doped Dy123 Melt-Solidified Bulks at Low Temperatures

We have previously reported that dilute impurity doping technique universally enhances the critical current density of RE123 superconductors. These doping effects on the J(c) properties depend on substituted cation sites. In this paper, we report the flux pinning properties of the dilute Sr- or Co-doped Dy123 melt-solidified bulks in a wide temperature range. It was found that the dilute Sr- doping effectively enhance the J(c) for Dy123 melt-solidified bulks with low level Dy/Ba substitution. For the dilute Sr- doped Dy123 samples, the temperature coefficient of J(c) in 30 kOe was found to be approximately two times larger than for undoped materials above 40 K, meaning that it is an effective method for developing high-J(c) RE123 materials operating at low temperatures.