Quadrupolar and magnetic interactions in antiferroquadrupolar ordering compound DyB2C2 studied by Y dilution

In order to elucidate quadrupolar and magnetic interactions in the antiferroquadrupolar (AFQ) and antiferromagnetic (AFM) ordering compound DyB2C2, 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 Dy1-xYxB2C2. The result 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-dimensional with strong AFQ interactions along the c-axis and weak ferroquadrupolar interactions in the c-plane. (author)