Datta Raktim, Pradhan Suman Kalyan, Saha Rafikul Ali, Kumar Ravi, Majumdar Subham, De Subodh Kumar
School of Physical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
School of Materials Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
J Phys Condens Matter. 2023 Feb 1;35(12). doi: 10.1088/1361-648X/acafc8.
We report rich magnetic behavior for Co-Ir based double perovskites consisting of different rare earth cations Pr and Nd: PrCoIrO(PCIO) and NdCoIrO(NCIO). Both oxides show an antisite disorder of 10% and a ferrimagnetic transition,FiMaround 96 K and 98 K respectively. The long range magnetic ordering is arising from the canted antiferromagnetic ordering between the Coand Irions. A prominent peak around 27 K in magnetization data of NCIO indicates that the total moment of Nd ion is antiferromagnetically coupled to the Co-Ir sublattice. The long range order of the Nd sublattice is corroborated by the evidence of an anomaly in specific heat at very low temperature. The compounds exhibit a maximum change of magnetic entropy of 0.57 (0.48) J kg.KatFiMin a magnetic field of 5 T. The strong spin-orbit coupling in 5states of Ir and cation disorder lead to the Mott insulating phase as found from the analysis of temperature dependent resistivity. These unique behaviors suggest an interesting interplay between localized Pr/Nd-4, itinerant Co-3and Ir-5electrons.
我们报道了由不同稀土阳离子Pr和Nd组成的Co-Ir基双钙钛矿PrCoIrO（PCIO）和NdCoIrO（NCIO）的丰富磁行为。两种氧化物均显示出10%的反位无序以及分别在约96 K和98 K的亚铁磁转变。长程磁有序源于Co和Ir离子之间的倾斜反铁磁有序。NCIO磁化数据中在约27 K处的一个显著峰表明Nd离子的总磁矩与Co-Ir亚晶格反铁磁耦合。极低温下比热异常的证据证实了Nd亚晶格的长程有序。在5 T磁场中，这些化合物在居里温度下表现出最大磁熵变0.57（0.48）J kg⁻¹ K⁻¹。从对温度依赖电阻率的分析可知，Ir的5d态中的强自旋轨道耦合和阳离子无序导致了莫特绝缘相。这些独特行为表明局域化的Pr/Nd-4f、巡游的Co-3d和Ir-5d电子之间存在有趣的相互作用。
