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

Magnetic Properties of MeB_{50} (Me = 3d Atom) Compounds

“…The largest magnitude of θ (-70 K) was observed for FeB 50 compound which agrees with data reported in [5] for B:Fe system at the corresponding composition. The nature of this AFM coupling, which is also observed in rare earth higher borides [9], is not yet understood.…”

Lattice Vibrations, MIR and FIR Optical Properties of Boron and Icosahedral Boron-Rich Borides II. β-Rhombohedral Structure Group

“…Approximately symmetrically the initial vibration is shifted towards higher, the Mn induced vibration towards lower frequencies. Obviously this change coincides with the inter-cluster interaction [39,55] infringing the whole structure, which means the unit cells with local clusters and those without clusters as well. This seems to be induced merely by a charge transfer than by a change of the bonding distances.…”

“…Very strong influences are to be expected, when in case of high interstitial doping a direct or indirect exchange interaction between these atoms arises. Such clusters were found by magnetical investigations on B:Mn and B:Fe [39,55],…”

“…The occupation of the A(l)(Me 1) position is assumed to be ineffective, because its distance from the B(15) atom seems to be too large. According to the results of ESR and magnetic susceptibility [39,55], clusters between A(l)(Me 1) and D(Me2) holes are formed already in the MnB 3330 composition. Hence the intensity of the vibration at 1166 cm -1 seems to be immediately correlated with the number of clusters of this local type.…”

“…The bonding conditions are additionally modified, when intercluster interactions take place. Hence the X-ray determination of atomic positions in such solid solutions must be assumed to have yielded average values of unit cells with occupied and unoccupied voids, and the real structure deformation in the unit cells with occupied sites may be stronger than reported [39,55],…”