Yatsuzuka Hayato, Haraguchi Yuya, Matsuo Akira, Kindo Koichi, Katori Hiroko Aruga
Department of Applied Physics, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan.
The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan.
Sci Rep. 2022 Feb 14;12(1):2429. doi: 10.1038/s41598-022-06467-2.
We have successfully synthesized new Ru double perovskite oxides SrLaInRuO and SrLaGaRuO, which are expected to be a spin-orbit coupled J = 0 Mott insulating ground state. Their magnetic susceptibility is much significant than that expected for a single Ru ion for which exchange coupling with other ions is negligible. Their isothermal magnetization process suggests that there are about 20 percent isolated spins. These origins would be the Ru/Ru magnetic defects, while the regular Ru sites remain nonmagnetic. Moreover, SrLaGaRuO shows a spin-glass-like magnetic transition at low temperatures, probably caused by isolated spins. The observed spin-glass can be interpreted by the analogy of a dilute magnetic alloy, which can be seen as a precursor to the mobile J = 1 exciton as a dispersive mode as predicted.
我们已成功合成了新型钌双钙钛矿氧化物SrLaInRuO和SrLaGaRuO，预计它们处于自旋轨道耦合J = 0的莫特绝缘基态。它们的磁化率比单个钌离子的预期值大得多，对于单个钌离子而言，与其他离子的交换耦合可忽略不计。它们的等温磁化过程表明存在约20%的孤立自旋。这些来源可能是钌/钌磁性缺陷，而规则的钌位点保持非磁性。此外，SrLaGaRuO在低温下表现出类似自旋玻璃的磁转变，可能是由孤立自旋引起的。观察到的自旋玻璃可以通过稀磁合金的类比来解释，如预测的那样，它可被视为作为色散模式的移动J = 1激子的前驱体。
