Many of the interesting properties observed in Ce- and Yb-based compounds are attributed to c-f interactions, with d-f interactions often considered negligible. However, there are compounds, such as CePt₃ and YbAl₃ [1,2], where d-f interactions play a significant role. Our study focuses on one such compound, YbCo₂, which belongs to the RCo₂ series (R being a rare earth element). These compounds exhibit strong d-f electron interactions and are known for their magnetic properties. We conducted a detailed study of the relatively unexplored YbCo₂ compound, which is expected to exhibit magnetic order. Our results provide evidence of a low-temperature magnetic anomaly, observed in specific heat, electrical resistivity, and magnetization measurements [3]. The transition temperature increases with the applied field, indicating a ferromagnetic nature of the anomaly. The origin of this anomaly will be discussed, along with new and unexpected findings that introduce this intriguing compound.
[1] Goremychkin E A et al., 2018 Science 359 186
[2] Cornelius A L et al., 2002 Phys. Rev. Lett. 88 117201
[3] Valenta et al., 2023 J. Phys.: Condens. Matter 35 285601