Electronic structure and thermodynamic properties of CeRh2Sn4 and LaRh2Sn4

Abstract

The electronic structure and thermodynamic properties of CeRh2Sn4 and LaRh2Sn4 are reported. The crystal structure of CeRh2Sn4 has been determined from single-crystal diffraction experiments. The Ce core-level x-ray photoemission spectra and Ce LIII x-ray absorption data unanimously indicate a stable trivalent state of the Ce ions in CeRh2Sn4, consistent with static magnetic susceptibility. Thermodynamic measurements for CeRh2Sn4 show a noncollinear antiferromagnetic ordering with a ferromagnetic component at TN≈3.2 K. There is evidence for spin fluctuations in both CeRh2Sn4 and LaRh2Sn4. A Fermi surface analysis reveals sections, which could generate 'nesting' instabilities and be responsible for the spin fluctuation effects. Both CeRh2Sn4 and LaRh2Sn4 exhibit slight homogeneity ranges and can be described by RE1+xRh2Sn4−x, where 0 \leq x \lesssim 0.2 for Ce and 0 \leq x \lesssim 0.1 in the case of La. Implantation of additional Ce atoms into the CeRh2Sn4 structure leads to a distinct lowering of TN and the weakening of the ferromagnetic component of the magnetic ground state, whereas for the La-based systems the alloying reduces the strong diamagnetism.