RT Journal Article
T1 Role of positional disorder in fully textured ensembles of Ising-like dipoles
A1 Alonso-Pereda, Juan José
A1 Allés, Bartolome
A1 Russier, Vincent
A1 Malherbe, Jean G.
K1 Dipolos magnéticos
AB We study by numerical simulation the magnetic order in ensembles of randomly packed magnetic spherical particles which, induced by their uniaxial anisotropy in the strong coupling limit, behave as Ising dipoles. We explore the role of the frozen disorder in the positions of the particles assuming a common fixed direction for the easy axes of all spheres. We look at two types of spatially disordered configurations. In the first one we consider isotropic positional distributions which can be obtained from the liquid state of the hard sphere fluid. We derive the phase diagram in the T -Φ plane where T is the temperature and Φ the volume fraction. This diagram exhibits long-range ferromagnetic order at low T for volume fractions above the threshold Φc = 0.157 predicted by mean-field calculations. For Φ ≲ Φc a spin-glass phase forms with the same marginal behavior found for other strongly disordered dipolar systems. The second type of spatial configurations we study are anisotropic distributions that can be obtained by freezing a dipolar hard sphere liquid in its polarized state at low temperature. This structural anisotropy enhances the ferromagnetic order present in isotropic hard sphere configurations.
PB American Physical Society (APS)
YR 2023
FD 2023-10
LK https://hdl.handle.net/10630/37216
UL https://hdl.handle.net/10630/37216
LA spa
NO Alonso Juan J. Allés, Bartolomé Russier, Vincent, Malherbe, Jean Guillaume,  Role of positional disorder in fully textured ensembles of Ising-like dipoles.   Phys. Rev. B 108, 134404 (2023).   DOI: https://doi.org/10.1103/PhysRevB.108.134404
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 19 ene 2026