Hall Resistance Measurements on Ce₂Ge₂Mg

Ce₂Ge₂Mg has a layered crystal structure in which the magnetic cerium ions form the Shastry Sutherland lattice in the tetragonal a-b plane, with the remaining Ge and Mg ions interstitial [1-3]. It belongs to a larger family of similarly structured R₂T₂X (R=Rare earth, T = Transition Metal, X = main group) materials [3]. Within this group Ce₂Ge₂Mg is of particular interest due to the magnetic f-electrons being below the fermi level, allowing for the study of the more localized f-orbital states within a metallic background. Additionally, there are predictions for topologically protected surface states within the magnetically ordered phase when T<T_N=9.3 K [4].



Our recent measurements on the longitudinal magnetoresistance show the presence of strong magnetic fluctuations in Ce₂Ge₂Mg at low temperatures and fields. In this talk I will discuss new measurements of the Hall resistance in the paramagnetic and antiferromagnetic states, their implications for the transport properties of the material, and their relation to the fluctuations noted in the longitudinal resistance data.

[1] Shastry, B. Sriram, and Bill Sutherland.Physica B+ C 108.1-3 (1981): 1069-1070.

[2] Kraft, Rainer, and Rainer Pöttgen. Monatshefte für Chemie 135 (2004): 1327-1334.

[3] Kim, M. S., and M. C. Aronson.Journal of Physics: Condensed Matter 23.16 (2011): 164204.

[4] Hwang, Yoonseok, et al. "npj Computational Materials 9.1 (2023): 65.