2008/03/06 by A. Biltmo, P. Henelius · 1 citation
Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Theoretical and Computational Physics #cond-mat.dis-nn #cond-mat.mtrl-sci #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevb.78.054437
published as Phys. Rev. B 78, 054437 (2008) · 6 pages, 9 figures
arxiv created 2008/03/06 · openalex publication_date 2008/08/25 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We analyze recent experiments on the dilute rare-earth compound LiHoxY_1\ensuremath-xF4 in the context of an effective Ising dipolar model. Using a Monte Carlo method we calculate the low-temperature behavior of the specific heat and linear susceptibility and compare our results to measurements. In our model the susceptibility follows a Curie-Weiss law at high temperature, \ensuremathχ\ensuremath∼1/(T\ensuremath-Tcw), with a Curie-Weiss temperature that scales with dilution, Tcw\ensuremath∼x, consistent with early experiments. We also find that the peak in the specific heat scales linearly with dilution, Cmax(T)\ensuremath∼x, in disagreement with recent experiments. This difference could be caused by the hyperfine interaction which is not included in our calculation. Experimental studies do not reach a consensus on the functional form of the susceptibility and specific heat, and in particular, we do not see reported scalings of the form \ensuremathχ\ensuremath∼T^\ensuremath-0.75 and \ensuremathχ\ensuremath∼exp(\ensuremath-T/T0). Furthermore, we calculate the ground-state magnetization as a function of dilution and re-examine the phase diagram around the critical dilution xc=0.24\ifmmode±\else\textpm\fi0.03. We find that the spin-glass susceptibility for the Ising model does not diverge below xc, while some recent experiments give strong evidence for a stable spin-glass phase in LiHo0.167Y0.833F4.