The magnetic behavior of single-crystal ${\mathrm{Ho}}_2{\mathrm{PdSi}}_3,$ crystallizing in an ${\mathrm{AlB}}_2$-derived hexagonal structure, is investigated by magnetic susceptibility $\left(\chi \right)$ and electrical resistivity $\left(\rho \right)$ measurements along two directions. There is no dramatic anisotropy in the high-temperature Curie-Weiss parameter or in the $\rho$ and isothermal magnetization data, though there is a noticeable anisotropy in the magnitude of $\rho$ between two perpendicular orientations. The degree of anisotropy is overall less prominent than in the Gd (which is an S-state ion) and Tb analogs. A point of emphasis is that this compound undergoes long-range magnetic ordering below 8 K as in the case of analogous Gd and Dy compounds. Considering this fact for these compounds with a well-localized f orbital, the spin-glass freezing noted for isomorphous U compounds in the recent literature could be attributed to the role of the f-ligand hybridization, rather than just Pd-Si disorder.

• Received 6 March 2002

DOI:https://doi.org/10.1103/PhysRevB.66.052409