The tetragonal σ phase and the hexagonal (hex) phase in the Mn–Si–V(Cr) transition-metal alloy systems are stable approximant phases of a dodecagonal (12-fold) quasicrystal that can be prepared in bulk quantities. We have synthesized samples of the σ and hex phases of composition Mn76Si18Cr6 and determined their magnetic properties. In the σ-Mn76Si18Cr6, a spin-freezing transition to a canonical spin glass phase was detected below Tf ≈ 8 K.
COBISS.SI-ID: 25421095
A. Zorko and coworkers from IJS in collaboration with Institute of Inorganic Chemistry, RWTH Aachen University, Aachen, Germany investigated also the ground state of the spatially-anisotropic triangular lattice CuNCN. In this novel quantum spin system, the magnetism is surprisingly suppressed. Local-probe studies including muon spin relaxation, electron spin resonance and nuclear magnetic resonance have shown that magnetic ordering is missing in this system down to the lowest experimentally accessible temperatures and that the magnetism is inhomogeneous.
COBISS.SI-ID: 24909863
Geometrical frustration of spin lattices leads to exotic collective magnetic ground states. A. Zorko and collaborators from Institut Néel, CNRS and Université Joseph Fourier, Grenoble, France investigated the ground state and magnetic excitations of a triangular lattice of triangles, realized in Ba3NbFe3Si2O14. This spin-5/2 iron system features a unique single-domain double-chiral ground state (triangular chirality of the order on each triangle and helicity of the order between planes). Employing inelastic neutron scattering they have discovered an unprecedented dynamical signature of the chiral ground state – a magnetic excitation branch that is completely chiral in the whole energy range.
COBISS.SI-ID: 25416231