Evidence for RKKY-type interaction in intermetallics, as derived from magnetic dilution of GdPdIn with Y or Th

Abstract

The magnetic properties of Gd x Y 1− x PdIn and Gd x Th 1− x PdIn (0< × ⩽ 1) were studied between 4.2 and 300 K. GdPdIn is ferromagnetic with T c ≈ 103 K, while T c ≈ θ p . Magnetic dilution with Y results in a linear decrease of both T c and θ p with x, even at low x. Upon dilution with Th, θ p exhibits a stronger initial decrease, followed by a sign reversal. It is argued that this points to a long range exchange interaction with a sign changing with the distance. The experimental findings are finally shown to be in close agreement with RKKY theory.