Bulk samples of magnesium diboride (MgB₂) doped with 0.5 wt% of the rare earth oxides (REOs) Nd₂O₃ and Dy₂O₃ (named B-ND and B-DY) prepared by standard powder processing, and wires of MgB₂ doped with 0.5 wt% Dy₂O₃ (named W-DY) prepared by a commercial powder-in-tube processing were studied. Investigations included x-ray diffractometry, scanning- and transmission electron microscopy, magnetic measurement of superconducting transition temperature (T _c), magnetic and resistive measurements of upper critical field (B _c2) and irreversibility field (B _irr), as well as magnetic and transport measurements of critical current densities versus applied field (J _cm(B) and J _c(B), respectively). It was found that although the products of REO doping did not substitute into the MgB₂ lattice, REO-based inclusions resided within grains and at grain boundaries. Curves of bulk pinning force density (F _p) versus reduced field (b = B/B _irr) showed that flux pinning was by predominantly by grain boundaries, not point defects. At all temperatures the F _p(b) of W-DY experienced enhancement by inclusion-induced grain boundary refinement but at higher temperatures F _p(b) was still further increased by a Dy₂O₃ additive-induced increase in B _irr of about 1 T at all temperatures up to 20 K (and beyond). It is noted that Dy₂O₃ increases B _irr and that it does so, not just at 4 K, but in the higher temperature regime. This important property, shared by a number of REOs and other oxides promises to extend the applications range of MgB₂ conductors.

通过标准粉末加工制备的掺杂有 0.5 wt% 稀土氧化物 (REO) Nd ₂ O ₃和 Dy ₂ O ₃ （命名为 B-ND 和 B-DY）的二硼化镁 (MgB ₂ ) 的散装样品，以及研究了通过商业粉管工艺制备的掺有0.5wt％Dy ₂ O ₃的MgB ₂ （命名为W-DY）。研究包括 X 射线衍射、扫描和透射电子显微镜、超导转变温度 ( T _c ) 的磁测量、上临界场 ( B _c2 ) 和不可逆场 ( B _irr ) 的磁和电阻测量，以及磁和电阻测量。临界电流密度与施加场的传输测量（分别为J _cm ( B ) 和J _c ( B )）。结果发现，虽然REO掺杂的产物没有取代到MgB ₂晶格中，但REO基夹杂物存在于晶粒内和晶界处。体积钉扎力密度 ( F _p ) 与减小场 ( b = B / B _irr ) 的曲线表明，磁通钉扎主要是由晶界而非点缺陷造成的。 在所有温度下，W-DY 的F _p ( b ) 均因夹杂物引起的晶界细化而得到增强，但在较高温度下， F _p ( b ) 仍因 Dy ₂ O ₃添加剂引起的B _irr增加而进一步增加。在高达 20 K（及以上）的所有温度下均为 1 T。值得注意的是，Dy ₂ O ₃增加了B _irr ，并且不仅在 4 K 下如此，而且在更高的温度范围内也是如此。许多 REO 和其他氧化物都具有这一重要特性，有望扩展 MgB ₂导体的应用范围。