Metamagnetic transition in the Kondo lattice compound CePt2Si2

CePt2Si2: A Kondo lattice compound with no magnetic ordering do

“…1 Its Kondo temperature as determined by specific heat is T K Ӎ 70 K. 2 At low temperature, its specific heat, electrical resistivity, and magnetic susceptibility display nonFermi-liquid behavior. 2,3 Whereas the thermal behavior of the specific heat C and electrical resistivity follow the predictions for a Fermi-liquid system in the range 4-10 K, at low temperature they strongly deviate from the expected behavior. The Sommerfeld ratio C/T increases steeply as the temperature T decreases and concomitantly has an approximate linear temperature dependence.…”

“…9 The signature of a metamagnetic transition which is perceptible for the as-grown crystal at Ϸ 2.5 T when the field is applied along the a axis has disappeared in the annealed crystal. Therefore the reported metamagnetic transition 3 is not an intrinsic physical property of CePt 2 Si 2 . We have performed additional magnetic susceptibility measurements down to 2 K. The results are presented in Fig.…”

“…2 It has been argued that a collapse of the magnetic susceptibility in the c plane occurs below 4 K, although this conclusion has been reached after applying a large correction to the measured susceptibility. 3 This correction was supposed to take into account an impurity contribution to the susceptibility. The low temperature dependence of the Sommerfeld ratio, resistivity, and susceptibility may reflect a low temperature magnetic phase transition.…”

“…As found previously, the magnetization is very weak with a large anisotropy in favor of the basal plane. 3 This anisotropy is explained by the crystal electric field acting on the Ce ions. 9 The signature of a metamagnetic transition which is perceptible for the as-grown crystal at Ϸ 2.5 T when the field is applied along the a axis has disappeared in the annealed crystal.…”

“…The fact that annealing increases the low temperature planar and axial susceptibilities seems to point out that the relatively large susceptibilities at low temperature is at least partly an intrinsic effect and not entirely due to impurities as suggested previously. 3 To settle the problem of the origin of the anomalous low temperature behavior of the susceptibilities, nuclear magnetic resonance ͑NMR͒ experiments on 195 Pt and 29 Si have to be performed. In Fig.…”