Speaker
Description
In our systematic exploration of the Eu-Pd-Sn ternary system, we have identified several new compounds, such as Eu$_2$Pd$_2$Sn, EuPd$_2$Sn$_4$, and EuPdSn$_2$. These Eu-based compounds often show a complex magnetic behavior. This behavior is unexpected since the intermetallics based on Eu$^{2+}$ (electron configuration 4f$^{7}$ and $^8$S$_{7/2}$ ground state) represent a pure spin system with $J=S=7/2$ and $L=0$ ($J$: total angular momentum; $S$: total spin angular momentum; $L$: total orbital angular momentum) which excludes crystal electric field effects. Consequently, these compounds are expected to exhibit negligible magnetic anisotropy although, on the contrary, they often show complex anisotropic magnetic ordering [1]. The interest in these compounds is due to the possible existence of topologically non-trivial magnetic textures that offer the potential for new magnetic information manipulation and storage technologies. For example, the magnetic structure of Eu$_{2}$Pd$_{2}$Sn shows significant analogies to the structure observed in EuNiGe$_{3}$ [2], possibly indicating the presence of a skyrmion lattice also for Eu$_{2}$Pd$_{2}$Sn [3].
In this work, we show the first results on a new compound synthesized in the Eu-Pd-Sn system, namely Eu$_{3}$Pd$_{4}$Sn$_{13}$. It crystallizes in the cubic Yb$_3$Rh$_4$Sn$_{13}$ structure type (space group P m -3 n) as confirmed by Rietveld refinement. The magnetic properties of this compound were investigated by measuring the magnetic susceptibility, the isothermal magnetization at different magnetic fields, and the specific heat. The trend of the inverse susceptibility as a function of temperature follows the Curie-Weiss plot with $\mu_{eff}=7.92$ $\mu_B$ in good agreement with the theoretical value of Eu$^{2+}$. Two effects were observed in the specific heat measurements, a very sharp effect at $6.5$ K pointing to a first-order transition, and a second at about 5 K. The magnetic susceptibility plot shows a magnetic kink at about $5$ K, which could indicate a complex interplay between antiferromagnetism and ferromagnetism.
Acknowledgements
Financial support from the Ministry of Higher Education and Scientific Research of Tunisia is gratefully acknowledged. This work was also supported by the project VEGA 1/0511/24.
References
[1] S. Seiro and C. Geibel, “Complex and strongly anisotropic magnetism in the pure spin system EuRh2Si2,” Journal of Physics: Condensed Matter, vol. 26, no. 4. IOP Publishing, p. 046002, Dec. 20, 2013. https://doi.org/10.1088/0953-8984/26/4/046002
[2] W. Iha et al., “Anomalous Hall Effect in Antiferromagnet EuNiGe3 with the Rashba-type Tetragonal Structure,” Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2019). Journal of the Physical Society of Japan, Mar. 18, 2020. https://doi.org/10.7566/jpscp.30.011092
[3] J. G. Sereni et al., "Evidence for magnetic dimers and skyrmion lattice formation in Eu2Pd2Sn," Physical Review B, vol. 108, no. 1. American Physical Society (APS), Jul. 24, 2023. https://doi.org/10.1103/physrevb.108.014427
