Density functional study on CeMo[sub 2]Si[sub 2]C

Abrupt Europium Valence Change in Eu2Pt6Al15 around 45 K

“…However, the availability of a second oxidation state results in numerous interesting physical phenomena. Mixed valences can be found (Eu 3 O 4 , 2 Sm 3 S 4 , 3 Eu 3 S 4 , 3a or EuPtP 4 ) as well as intermetallic valence fluctuation materials (e.g., CeAl 3 , 5 Yb 4 Pt 9 Ga 24 , 6 CeMo 2 Si 2 C, 7 CeRu 1−x Ni x Al, 8 Ce 2 Rh 3 Sn 5 , 9 CeCu 2 Si 2 , 10 EuCu 2 Si 2 , 10,11 YbCu 2 Si 2 10 ). A rather rare feature is a temperature or pressure dependent valence phase transition.…”

Observation of ferromagnetism in CeCr2Si2C single crystals

“…25 The coexistence of Ce 3+ and Ce 4+ is due to the little energy difference between them. The coexistence of Ce 3+ and Ce 4+ ions is also reported in other Ce-based compounds such as CeMo 2 Si 2 C, which has the same crystal structure as CeCr 2 Si 2 C. 9,15 In lanthanides, the FM usually originates from the magnetic 4f exchange mediated indirectly via the electrons through RKKY interaction. 26,27 The metal behavior and existence of Ce 3+ having a 4f1 orbital indicate that the FM behavior is from the RKKY interaction in CeCr 2 Si 2 C. The FM transition temperature is between 10-20 K by applying Curie-Weiss tting for the c −1 -T (the inset of Fig.…”

“…1a). The refined lattice parameters ( a = b = 4.018(3) Å, c = 5.282(7) Å, α = β = γ = 90°) are smaller than those of PrMo 2 Si 2 C ( a = 4.214 Å, c = 5.409 Å), implying that Ce-ions show intermediate valence state in CeCr 2 Si 2 C. 9,15 C plays a crucial role in the formation of stabilized CeCr 2 Si 2 phase. 11 The insertion of C shifts the space group of CeCr 2 Si 2 from I 4/ mmm to P 4/ mmm of CeCr 2 Si 2 C. 11 The results of energy dispersive X-ray spectroscopy (EDS) for single crystals show that the single crystal is composed of Ce, Cr, Si, and C with an atomic ratio of ∼1 : 2 : 2 : 1 (see Fig.…”

“…At low temperatures, the χ values (∼0.008 emu mol −1 Oe −1 , H ‖ ab ) are much smaller than that of PrCr 2 Si 2 C, 12,24 probably ascribing to the coexistence of Ce 3+ and Ce 4+ ions because Ce 4+ has no magnetic contribution due to its 4f 0 orbital. 12,15 X-ray photoelectron spectroscopy (XPS) results (Fig. 3c and d) elucidate the coexistence of Ce 3+ and Ce 4+ because the binding energies of Ce 4+ 3d 3/2 , Ce 4+ 3d 5/2 , Ce 3+ 3d 3/2 and Ce 3+ 3d 5/2 are centered at ∼916.8, ∼898.1, ∼900.7, and ∼882.3 eV, respectively.…”