Static magnetic and EPR studies of iron in the β-rhombohedral boron structure

Abstract

Abstract The magnetic properties of iron atoms and their distribution in β-rhombohedral boron were studied using EPR and static magnetic susceptibility measurements in the temperature range 3.6–300 K. It has been shown that, for low concentrations, the iron atoms occupy the A holes of the β-rhombohedral structure and, after the concentration is increased, the D holes. Iron atoms in the A and D holes interact and form antiferromagnetic clusters (pairs). Iron atoms in the A hole are responsible for compensation of the hole trapping levels near the valence band edge. The charge state of iron in the A hole is Fe3+ and, as a result of the strong crystalline field of the ligands, a low spin value, S = 1 2 , was found. Iron in the D hole is in the Fe2+ state and experiences an intermediate crystal field strength with μeff = 4.20.