Hybridization model for the magnetic-ordering behavior of uranium- and cerium-based 1:2:2 intermetallic compounds

It is shown that the occurrence of magnetic ordering in U${\mathit{T}}_2$ ${\mathit{X}}_2$ and Ce${\mathit{T}}_2$ ${\mathit{X}}_2$ intermetallic compounds, when T denotes a transition metal and X represents Si or Ge, and the magnetic-ordering temperatures in those compounds that order magnetically, are related to the strength of the f-d hybridization. Values for this hybridization strength in various series of such ternary and pseudoternary compounds are obtained via a semiquantitative band-structural approach, and the systematics in these values are used to determine the ordering trends in the phase diagram of a Kondo lattice.