Characterization of the valence transition inYbxIn1−

Crystal field study in rare-earth-dopedLuInNi4

“…7,10,11 The crystalline electric-field splitting in this compound appears to be comparable to the spinfluctuation temperature and consequently does not significantly influence the ground state. [7][8][9][10][11][12][13] In contrast, CFE and the RKKY interactions are dominant for YbAuCu 4 , YbPdCu 4 , and YbInNi 4 .…”

“…Extensive studies 2 of susceptibility, specific heat, resistivity, Yb Mossbauer, lattice parameter, L III x-ray absorption, and NMR 3,4 are consistent with aϷ0.45% volume expansion below T v , 5 and an Yb valence change from zϷ2.9 above to zϷ2.8 below T v . 4 This material forms in the cubic AuBe 5 (C15b,F43m)-type structure 5 and, as other isomorphic Ybbased variants, it has interesting properties resulting from the interplay among Kondo effect, crystal-field effects ͑CFE͒, and the Ruderman-Kittel-Kasuya-Yosida ͑RKKY͒ interactions.…”

“…The series of intermetallic compounds YbA(Cu,Ni) 4 (A ϭtransition metal͒ have been extensively studied since the discovery of the first-order isostructural phase transition at T v Ϸ40 K in the intermediate valence compound YbInCu 4 .…”

“…13 Resistivity, specific heat, and magnetization measurements 13 15 Because the crystal-field scheme, and associated ground-state degeneracy, is important for guiding the interpretation of the low-T properties of these materials, we have performed further CFE investigations in rare-earth-doped LuInNi 4 in order to understand the role of CFE in YbInNi 4 and the different observation reported in Refs. 13 and 14.…”

“…4 This material forms in the cubic AuBe 5 (C15b,F43m)-type structure 5 and, as other isomorphic Ybbased variants, it has interesting properties resulting from the interplay among Kondo effect, crystal-field effects ͑CFE͒, and the Ruderman-Kittel-Kasuya-Yosida ͑RKKY͒ interactions. 6 YbAgCu 4 , for example, has a relatively large linear coefficient of specific heat (␥Ϸ240 mJ/mol K 2 ), 7,8 and a temperature-dependent magnetic susceptibility with a maximum at Ϸ35 K ͑Ref.…”