Magnetism in double perovskite oxides of the formula A₂BB'O₆ has been a subject of great interest and intensive research in condensed matter physics. In this paper, Ln₂CuRuO₆ (A = La, Pr) samples were synthesized by solid-state reaction method, and we investigated their structural and magnetic properties. The new double perovskite compound Pr₂CuRuO₆ stabilizes in the monoclinic P2₁/n structure with an antisite defect fraction of ~ 3% between Cu and Ru sites. Our structural analysis indicates the severe deformation of Cu-O-Ru bond angle, as La³⁺ is replaced by the smaller rare earth ion Pr³⁺. For Pr₂CuRuO₆, the observed ferromagnetic transition temperature (Tc = 32 K) is higher than that of La₂CuRuO₆ (Tc = 15 K), which may be possibly associated with the enhanced magnetic interaction due to the distorted Cu-O-Ru bond angle. In addition, the anomalous phenomenon of ZFC susceptibility at low temperature suggests a degree of magnetic frustration and can be attributable to the intrinsic antisite defect in Pr₂CuRuO₆. The first principle calculations confirm a ferromagnetic Cu-Ru exchange interaction in Pr₂CuRuO₆, which is different from the antiferromagnetic case for La₂CuRuO₆.

式A ₂ BB'O _6的双钙钛矿氧化物中的磁性一直是凝聚态物理研究的热点和深入研究的课题。本文通过固相反应法合成了Ln ₂ CuRuO ₆（A = La，Pr）样品，并研究了它们的结构和磁性。新的双钙钛矿化合物Pr ₂ CuRuO ₆稳定在单斜晶P 2 ₁ / n结构中，Cu和Ru位点之间的位点缺陷分数约为3％。我们的结构分析表明，Cu-O-Ru键角的严重变形为La ³⁺被较小的稀土离子Pr ³⁺代替。对于Pr ₂ CuRuO ₆，观察到的铁磁转变温度（Tc = 32 K）高于La ₂ CuRuO ₆（Tc = 15 K），这可能与由于Cu-O扭曲而增强的磁相互作用有关。 -Ru键角。此外，低温下ZFC磁化率的异常现象表明存在一定程度的磁挫败，并且可归因于Pr ₂ CuRuO _6中固有的反位缺陷。第一原理计算证实了Pr ₂ CuRuO _6中的铁磁性Cu-Ru交换相互作用，这与La ₂ CuRuO ₆的反铁磁情况不同。