Electronic structure and magnetic properties of the Ce₂MnGe₆ compound

Chem. Met. Alloys 1 (2008) 88-91

https://doi.org/10.30970/cma1.0010

A. SZYTUŁA, B. PENC, Yu. GORELENKO, M. KONYK, K. TOMALA, A. WINIARSKI

Magnetization, magnetic susceptibility and X-ray photoemission measurements were performed on a Ce₂MnGe₆ polycrystalline sample. This compound crystallizes in an orthorhombic Ce₂CuGe₆-type structure (space group Amm2). The Ce atoms occupy two nonequivalent sites, while the Mn atoms only one site. The magnetic data indicate that the compound is a ferrimagnet with the Curie temperature T_C = 150 K. The magnetic moment determined from the magnetization curve measured at 2 K increases from 1.9 μ_B for H ≈ 0 to 2.5 μ_B for H = 50 kOe. Above T_C the reciprocal magnetic susceptibility fulfills the Curie-Weiss law with the effective magnetic moment equal 5.3 μ_B. The valence band gives a small peak at 0.3 eV below the Fermi level and a broad one with the maximum at 2.1 eV, corresponding to the Mn 3d states. The structure of the Ce 3d_5/2 and Ce 3d_3/2 XPS spectra has been interpreted in terms of the Gunnarsson-Schönhammer theory. Two final-state contributions of f¹ and f², exhibiting a spin-orbit splitting of Δ_SO = 18.7 eV, were clearly observed. From the intensity ratio r = I(f²)/[I(f¹) + I(f²)] = 0.20 a hybridization energy equal 93 eV was determined.

Temperature dependence of the magnetic moment and the reciprocal magnetic susceptibility of Ce₂MnGe₆.

Keywords

Ternary rare earth germanides / Magnetic ordering / Electronic structure