Probing the magnetic ground state of single crystalline CeTiSb.

Motivated by the report of superconductivity in RTiSb (R  =  La and Ce) and possibly NdTiSb at  ∼4 K, we grew single crystals of LaTiSb and CeTiSb by the high-temperature solution method using Sn as a flux. While in both compounds we observed a superconducting transition at 3.7 K for resistivity and low-field magnetization, our data conclusively show that it arose from residual Sn flux present in the single crystals. In particular, the heat capacity data do not present any of the anomalies expected from a bulk superconducting transition. The anisotropic magnetic properties of CeTiSb, crystallizing in a hexagonal P6/mcm structure, were studied in detail. We find that the Ce ions in CeTiSb form a Kondo lattice and exhibited antiferromagnetic ordering at 5.5 K with a reduced moment and a moderately normalized Sommerfeld coefficient of 598 mJ/mol K. The characteristic single-ion Kondo energy scale was found to be  ∼8 K. The magnetization data were subjected to a crystal electric field (CEF) analysis. The experimentally observed Schottky peak in the 4f-electron heat capacity of CeTiSb was reproduced fairly well by the energy levels derived from the CEF analysis.