  We investigate the finite-temperature properties of an Anderson lattice with
regularly depleted impurities. The physics of this model is ruled by two
different magnetic exchange mechanisms: conventional
Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction at weak hybridization strength
V and a novel inverse indirect magnetic exchange (IIME) at strong V, both
favoring a ferromagnetic ground state. The stability of ferromagnetic order
against thermal fluctuations is systematically studied by static mean-field
theory for an effective low-energy spin-only model emerging perturbatively in
the strong-coupling limit as well as by dynamical mean-field theory for the
full model. The Curie temperature is found at a maximum for a half-filled
conduction band and at intermediate hybridization strengths in the crossover
regime between RKKY and IIME.
