2007/02/28 by G. Bouzerar, Georges Bouzerar, O. Cépas +1 · 1 citation
Materials Science · Mathematics · Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Curie temperature #Exchange interaction #Ferromagnetism #Hamiltonian (control theory) #Homogeneous #Lattice (music) #Magnetic and transport properties of perovskites and related materials #Magnetism #Materials science #Mathematics #Monte Carlo method #Physics #Physics of Superconductivity and Magnetism #Spin (aerodynamics) #Statistical physics #Statistics #Thermodynamics #cond-mat.dis-nn #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.76.020401
accepted for publication in Phys. Rev. B (rapid comm.)
openalex publication_date 2007/07/02 · arxiv created 2007/07/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the effects of short-range-correlated disorder arising from chemical dopants or local lattice distortions on the ferromagnetism of 3d double exchange systems. For this, we integrate out the carriers and treat the resulting disordered spin Hamiltonian within a local random phase approximation, whose reliability is shown by direct comparison with Monte Carlo simulations. We find large-scale inhomogeneities in the charge, couplings, and spin densities. Compared with the homogeneous case, we obtain larger Curie temperatures (TC) and very small spin stiffnesses (D). As a result, the large variations of \fracDTC measured in manganites may be explained by correlated disorder. We also provide a microscopic model for Griffiths phases in double exchange systems.