Electronic structure and thermodynamic properties ofCeRh2Sn4 andLaRh2Sn4

Abstract

The electronic structure and thermodynamic properties ofCeRh2Sn4 andLaRh2Sn4 are reported. Thecrystal structure of CeRh2Sn4 has been determined from single-crystal diffraction experiments. The Ce core-level x-ray photoemission spectraand Ce LIII x-ray absorption data unanimously indicate a stable trivalent state of the Ce ions inCeRh2Sn4, consistent with static magnetic susceptibility. Thermodynamic measurements forCeRh2Sn4 show a noncollinear antiferromagnetic ordering with a ferromagnetic component atTN≈3.2 K. There is evidence for spin fluctuations in bothCeRh2Sn4 andLaRh2Sn4. A Fermi surface analysis reveals sections, which could generate ‘nesting’instabilities and be responsible for the spin fluctuation effects. BothCeRh2Sn4 andLaRh2Sn4 exhibit slight homogeneity ranges and can be described byRE1+xRh2Sn4−x, where for Ce and in the case of La. Implantation of additional Ce atoms into theCeRh2Sn4 structure leads to adistinct 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.