Magnetic ordering in frustratedCe5Ni2Si3

Inhomogeneous Superconducting Behaviour in $$\hbox {La}_{5}\hbox {Ni}_{2}\hbox {Si}_{3}$$ La 5 Ni 2

“…Based on the measurements of ρ(T ) and χ(T ), we have found that La 5 Ni 2 Si 3 undergoes a superconducting phase transition below T c = 2.3 K. Our results are in agreement with the previous observations of Lee et al [9] who noticed the appearance of a superconducting transition in ρ(T ) at about 1.8 K. We have found that the investigated compound behaves as a type-II superconductor. The occurrence of three step-like transitions in the resistivity at 2.3, 1.8 and 0.77 K, before ρ(T ) reaches a clear limit of superconducting state at 0.45 K, and lack of the characteristic specific heat jump in the zero-field C p (T ) data imply that the superconductivity in the investigated compound is inhomogeneous and is rather a consequence of the spurious contribution from a trace of the binary La-Ni phase.…”

“…On the other hand, it should be noted here that the superconducting behaviour in La 5 Ni 2 Si 3 may originate from the other reason, namely from the coexistence of the superconducting phase and magnetic correlations. At this point, it is pertinent to note that the 4f electron counterpart Ce 5 Ni 2 Si 3 is a geometrically frustrated magnet with T N 5.7-7.3 K [9,27,28]. The long-range magnetic order below T N is characterized by competing interactions between Ce ions, where the magnetic moments are strongly frustrated.…”

“…As far as could be ascertained, the comprehensive studies of superconducting properties have not yet been reported to date for La 5 Ni 2 Si 3 . The only report indicating the occurrence of a superconducting transition in La 5 Ni 2 Si 3 was communicated by Lee et al [9] based on the resistivity measurements. With this motivation, in this paper we report the results of X-ray diffraction, electrical resistivity as well as the low-temperature magnetization and specific heat measurements, but mainly we focus on the superconducting properties of La 5 Ni 2 Si 3 .…”

“…Among the ternary systems, there is also another interesting pair of intermetallics, namely (Ce, La) 5 Ni 2 Si 3 , where Ce 5 Ni 2 Si 3 is a heavy fermion geometrically frustrated magnetic compound, whereas La 5 Ni 2 Si 3 is its non-magnetic analogue with superconducting transition at T c 1.8 K [9]. La 5 Ni 2 Si 3 crystallizes in the hexagonal space group P63/m of the Ce 5 Ni 2 Si 3 structure type (see Fig.…”

Valence Band and Core Levels of Ce5Ni2Si3Crystal Studied by X-ray Photoemission Spectroscopy

“…This compound exhibits a relatively large electronic specific heat coefficient γ = 263−300 mJ K −2 mol −1 , typical of the Kondo systems [1][2][3]. In connection with the observations of the large effective mass and the presence of the magnetic ordering one can expect a large degree of localization of the Ce(4f ) states.…”