Magnetic properties of the cerium monochalcogenides

Transport properties and crystal field energy in CeTe

“…To (2)). From equation (6) and the experimental value TM ~ 8 K, we find J ~ 26 K, which value is in very good agreement with previous determinations [8]. po can then be deduced by fitting the experimental curve ap~aT by the theoretical law deduced from (2) and (4).…”

“…The crystal growth and electrical measurement techniques were described elsewhere [2,5] [7], but have the same order of magnitude as in CeAs [8,9]. This is a surprising result, because based on a simple consideration of valence one would predict the cerium monochalcogenides to be more conducting than the monopnictides.…”

Competition of exchange and crystal field interactions in cerium monopnictides and monochalcogenides

“…This series of strongly correlated electron systems offers the opportunity to vary systematically, through chemical pressure, the lattice constant and the cerium separation on going down the pnictogen or chalcogen column, and hence tailor the degree of 4 f localization from the strongly localized limit in the heavier systems to to the weakly localized limit in the lighter systems. [1][2][3][4][5][6][7] The sensitivity of the hybridization, Coulomb exchange, and crystal-field ͑CF͒ interactions to the chemical environment gives rise to a variety of unusual magnetic properties.…”

“…The low temperature magnetic moment increases with increasing lattice constant for the pnictides from 0.80 B in CeP to 2.1 B in CeBi, 1-2 and decreases with increasing lattice constant for the chalcogenides from 0.57 B in CeS to 0.3 B in CeTe. [3][4][5] The magnetic moment collapse from CeSb to CeTe, with both systems having about the same lattice constant, is indicative of the sensitivity of the exchange interactions to the chemical environment. The ordering temperature increases from 8 K in CeP to 26 K in CeBi for the pnictides, whereas it decreases from 8.4 K in CeS to an unusually low 2.2 K in CeTe.…”

“…The ordering temperature increases from 8 K in CeP to 26 K in CeBi for the pnictides, whereas it decreases from 8.4 K in CeS to an unusually low 2.2 K in CeTe. [1][2][3][4][5] An unusual feature of the cerium series is the large suppression of the CF splitting of the Ce 3ϩ free-ion 4 f 5/2 multiplet from values expected from the behavior of the heavier isostructural rare-earth monopnictides. 8 In both the cerium monopnictides and monochalcogenides, the CF splitting between the ⌫ 7 doublet and the ⌫ 8 quartet decreases with increasing anion size, from 150 K for CeP to 8 K in CeBi and from 140 K for CeS to 32 K for CeTe, and it is about the same in both series, a rather surprising result in view of the additional valence electron on the chalcogen ion.…”