Intermediate valence inSmSbxS1−xalloys

Abstract

Results are presented for lattice-parameter and magnetic-susceptibility measurements on a series of solid solutions SmSb"S~". Low-temperature magnetic-susceptibility measurements indicate an inhomogeneous mixed valence for alloys containing low antimony concentrations and a homogeneous intermediate valence at larger concentrations. The susceptibilities of antimony-rich samples illustrate the disappearance of the antiferromagnetic ordering observed in pure SmSb. The alloys of intermediate composition display a nonmagnetic ground state associated with intermediate valence of the samarium cations. The effect of slight sulfur substitution in SmSb on crystalline electric fields is also discussed.

Anomalous quantum oscillations and evidence for a non-trivial Berry phase in SmSb

“…1 a, where the data up to 300 K is shown in the inset. The ρ(T ) data show a small hump at around 65 K, which is explained as resulting from the splitting of the crystalline electric fields [40], as well as a sharp drop of ρ(T ) at the antiferromagnetic transition at T N = 2.2 K [41]. While T N changes very little in applied magnetic fields [42], an upturn appears in ρ(T ) at low temperatures, which becomes more pronounced as the field is increased.…”

Electronic structure of samarium monopnictides and monochalcogenides

“…The Sm chalcogenides are nonmagnetic, 1 while the pnictides are antiferromagnetic with very low Néel temperatures. 34,35 In the present work the spin-polarized energy functional is not used to describe interatomic magnetism but rather to describe the intra-atomic exchange interactions. By Hund's first rule, the total spin of the f 5 or f 6 ion will be 5 / 2 or 3, and the ensuing energy gain is reasonably well described with the LSD exchange energy.…”

“…The proximity of the f 6 states is also probed by doping experiments starting from the pnictide and alloying with chalcogenides. 34,35,53 For SmAs, doping with S or Se does not indicate valence instability for S concentrations up to 40 % 53 or Se concentrations up to 30 %, 34 which suggests that in fact the extra electron of the chalcogen is not transferred into Sm f states, speaking against the presence of the unoccupied f band right at the Fermi level. On the other hand, when S is doped into SmSb the valency of Sm is seen to decrease already at low concentrations of S. 35 It seems that more experimental as well as theoretical research, including alloy calculations, is needed to elucidate this issue further.…”

“…The proximity of the f 6 states is also probed by doping experiments starting from the pnictide and alloying with chalcogenides. 34,35,53 For SmAs, doping with S or Se does not indicate valence instability for S concentrations up to 40% ͑Ref. 53͒ or Se concentrations up to 30%, 34 which suggests that in fact the extra electron of the chalcogen is not transferred into Sm f states, speaking against the presence of the unoccupied f band right at the Fermi level.…”

“…53͒ or Se concentrations up to 30%, 34 which suggests that in fact the extra electron of the chalcogen is not transferred into Sm f states, speaking against the presence of the unoccupied f band right at the Fermi level. On the other hand, when S is doped into SmSb the valency of Sm is seen to decrease already at low concentrations of S. 35 It seems that more experimental as well as theoretical research, including alloy calculations, is needed to elucidate this issue further.…”