Magnetic materials at finite temperatures: thermodynamics and combined spin and molecular dynamics derived from first principles calculations
Abstract
We present a unified approach to describe the combined behavior of the atomic and magnetic degrees of freedom in magnetic materials. Using Monte Carlo simulations directly combined with first principles the Curie temperature can be obtained ab initio in good agreement with experimental values. The large scale constrained first principles calculations have been used to construct effective potentials for both the atomic and magnetic degrees of freedom that allow the unified study of influence of phononmagnon coupling on the thermodynamics and dynamics of magnetic systems. The MC calculations predict the specific heat of iron in near perfect agreement with experimental results from 300K to above Tc and allow the identification of the importance of the magnonphonon interaction at the phasetransition. Further Molecular Dynamics and Spin Dynamics calculations elucidate the dynamics of this coupling and open the potential for quantitative and predictive descriptions of dynamic structure factors in magnetic materials using first principlesderived simulations.
 Authors:
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
 Univ. of Georgia, Athens, GA (United States). Center for Simulational Physics
 Univ. of North Carolina, Asheville, NC (United States). Dept. of Physics
 Univ. of Tennessee, Knoxville, TN (United States). National Inst. for Computational Sciences
 Florida State Univ., Tallahassee, FL (United States). Dept. of Physics
 Publication Date:
 Research Org.:
 Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF) and Center for Defect Physics (CDP)
 Sponsoring Org.:
 USDOE Office of Science (SC)
 OSTI Identifier:
 1222549
 DOE Contract Number:
 AC0500OR22725
 Resource Type:
 Conference
 Resource Relation:
 Conference: XXVI IUPAP Conference on Computational Physics, CCP2014, Boston, MA (United States), 1114 Aug 2014
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; MAGNETIC MATERIALS; COMPUTERIZED SIMULATION; MOLECULAR DYNAMICS METHOD; SPIN; CURIE POINT; IRON; PHONONS; SPECIFIC HEAT; DEGREES OF FREEDOM; MONTE CARLO METHOD; THERMODYNAMICS; STRUCTURE FACTORS; MAGNONS; COUPLING; POTENTIALS; PHASE TRANSFORMATIONS; INTERACTIONS
Citation Formats
Eisenbach, Markus, Perera, Meewanage Dilina N., Landau, David P, Nicholson, Don M., Yin, Junqi, and Brown, Greg. Magnetic materials at finite temperatures: thermodynamics and combined spin and molecular dynamics derived from first principles calculations. United States: N. p., 2015.
Web.
Eisenbach, Markus, Perera, Meewanage Dilina N., Landau, David P, Nicholson, Don M., Yin, Junqi, & Brown, Greg. Magnetic materials at finite temperatures: thermodynamics and combined spin and molecular dynamics derived from first principles calculations. United States.
Eisenbach, Markus, Perera, Meewanage Dilina N., Landau, David P, Nicholson, Don M., Yin, Junqi, and Brown, Greg. 2015.
"Magnetic materials at finite temperatures: thermodynamics and combined spin and molecular dynamics derived from first principles calculations". United States.
doi:. https://www.osti.gov/servlets/purl/1222549.
@article{osti_1222549,
title = {Magnetic materials at finite temperatures: thermodynamics and combined spin and molecular dynamics derived from first principles calculations},
author = {Eisenbach, Markus and Perera, Meewanage Dilina N. and Landau, David P and Nicholson, Don M. and Yin, Junqi and Brown, Greg},
abstractNote = {We present a unified approach to describe the combined behavior of the atomic and magnetic degrees of freedom in magnetic materials. Using Monte Carlo simulations directly combined with first principles the Curie temperature can be obtained ab initio in good agreement with experimental values. The large scale constrained first principles calculations have been used to construct effective potentials for both the atomic and magnetic degrees of freedom that allow the unified study of influence of phononmagnon coupling on the thermodynamics and dynamics of magnetic systems. The MC calculations predict the specific heat of iron in near perfect agreement with experimental results from 300K to above Tc and allow the identification of the importance of the magnonphonon interaction at the phasetransition. Further Molecular Dynamics and Spin Dynamics calculations elucidate the dynamics of this coupling and open the potential for quantitative and predictive descriptions of dynamic structure factors in magnetic materials using first principlesderived simulations.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2015,
month = 1
}

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