Quadrupolar and Magnetic Interactions in Antiferroquadrupolar Ordering Compound DyB₂C₂Studied by Y Dilution

Abstract

In order to elucidate quadrupolar and magnetic interactions in the antiferroquadrupolar (AFQ) and antiferromagnetic (AFM) ordering compound DyB 2 C 2 , neutron diffraction experiments were performed on powdered and single-crystalline samples in addition to reexamination of specific heat and magnetization properties on the Y-diluted system Dy 1- x Y x B 2 C 2 . The results suggest that there is a percolation threshold at x =0.4–0.5 for the AFQ ordering. The broadening behavior of magnetic reflection peaks by the Y dilution suggests that the AFQ interaction is probably pseudo-one-dimensional with strong AFQ interactions along the c -axis and weak ferroquadrupolar interactions in the c -plane.