skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Effective anisotropy due to the surface of magnetic nanoparticles

Abstract

Analytical solution has been discovered for the second-order effective anisotropy of magnetic nanoparticles of a cubic shape due to the surface anisotropy (SA) of the Néel type. Similarly to the spherical particles, for the simple cubic lattice the grand-diagonal directions (±1,±1,±1) are favored by the effective cubic anisotropy but the effect is twice as strong. Uniaxial core anisotropy and applied magnetic field cause screening of perturbations from the surface at the distance of the domain-wall width and reduce the effect of SA near the energy minima. Yet, screening disappears near the uniaxial energy barrier, and the uniform barrier state of larger particles may become unstable. For these effects the analytical solution is obtained as well, and the limits of the additive formula with the uniaxial and effective cubic anisotropies for the particle are established. Thermally-activated magnetization-switching rates have been computed by the pulse-noise technique for the stochastic Landau-Lifshitz equation for a system of spins.

Authors:
 [1]
  1. City Univ. of New York (CUNY), NY (United States)
Publication Date:
Research Org.:
City Univ. of New York (CUNY), NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1593712
Alternate Identifier(s):
OSTI ID: 1466858
Grant/Contract Number:  
[FG02-93ER45487]
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
[ Journal Volume: 98; Journal Issue: 5]; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; magnetic nanoparticles; surface anisotropy; stochastic dynamics

Citation Formats

Garanin, D. A. Effective anisotropy due to the surface of magnetic nanoparticles. United States: N. p., 2018. Web. doi:10.1103/PhysRevB.98.054427.
Garanin, D. A. Effective anisotropy due to the surface of magnetic nanoparticles. United States. doi:10.1103/PhysRevB.98.054427.
Garanin, D. A. Mon . "Effective anisotropy due to the surface of magnetic nanoparticles". United States. doi:10.1103/PhysRevB.98.054427. https://www.osti.gov/servlets/purl/1593712.
@article{osti_1593712,
title = {Effective anisotropy due to the surface of magnetic nanoparticles},
author = {Garanin, D. A.},
abstractNote = {Analytical solution has been discovered for the second-order effective anisotropy of magnetic nanoparticles of a cubic shape due to the surface anisotropy (SA) of the Néel type. Similarly to the spherical particles, for the simple cubic lattice the grand-diagonal directions (±1,±1,±1) are favored by the effective cubic anisotropy but the effect is twice as strong. Uniaxial core anisotropy and applied magnetic field cause screening of perturbations from the surface at the distance of the domain-wall width and reduce the effect of SA near the energy minima. Yet, screening disappears near the uniaxial energy barrier, and the uniform barrier state of larger particles may become unstable. For these effects the analytical solution is obtained as well, and the limits of the additive formula with the uniaxial and effective cubic anisotropies for the particle are established. Thermally-activated magnetization-switching rates have been computed by the pulse-noise technique for the stochastic Landau-Lifshitz equation for a system of spins.},
doi = {10.1103/PhysRevB.98.054427},
journal = {Physical Review B},
number = [5],
volume = [98],
place = {United States},
year = {2018},
month = {8}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 2 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Magnetic properties of spherical fcc clusters with radial surface anisotropy
journal, May 1995


Effect of surface anisotropy on the hysteretic properties of a magnetic particle
journal, January 2002

  • Dimian, M.; Kachkachi, H.
  • Journal of Applied Physics, Vol. 91, Issue 10
  • DOI: 10.1063/1.1450846

Surface effects on ferromagnetic resonance in magnetic nanocubes
journal, November 2016


Influence of surface anisotropy on magnetization distribution in a single-domain particle
journal, August 2008

  • Usov, N. A.; Grebenshchikov, Yu. B.
  • Journal of Applied Physics, Vol. 104, Issue 4
  • DOI: 10.1063/1.2967709

Surface effects in metallic iron nanoparticles
journal, January 1994


Constrained Monte Carlo method and calculation of the temperature dependence of magnetic anisotropy
journal, August 2010


Random Fields, Topology, and the Imry-Ma Argument
journal, March 2014


ac susceptibility of an assembly of nanomagnets: Combined effects of surface anisotropy and dipolar interactions
journal, September 2014


Modelling of the influence of the Néel surface anisotropy on the enhancement of the magnetic anisotropy in Co nanoparticle
journal, February 2009


Hysteretic properties of a magnetic particle with strong surface anisotropy
journal, November 2002


Magnetic anisotropy in single clusters
journal, January 2004


Ferromagnetic resonance in systems with competing uniaxial and cubic anisotropies
journal, March 2007


Surface anisotropy in giant magnetic coercivity effect of cubic granular FeCo/SiO2 and NiCo/SiO2 films: A comparison with Néel’s theory
journal, August 1999

  • Chen, Chen; Kitakami, Osamu; Okamoto, Satoshi
  • Journal of Applied Physics, Vol. 86, Issue 4
  • DOI: 10.1063/1.371024

Surface effects in noninteracting and interacting γ-Fe2O3 nanoparticles
journal, May 2003


The role of vortices in the three-dimensional random-field xy model
journal, September 2013


Magnetic Anisotropy of a Single Cobalt Nanocluster
journal, May 2001


Formation Mechanism of Fe Nanocubes by Magnetron Sputtering Inert Gas Condensation
journal, March 2016


Random field x y model in three dimensions
journal, December 2013


Theory of magnetic interface anisotropy
journal, May 1993


Ferromagnetic nanoparticles with strong surface anisotropy: Spin structures and magnetization processes
journal, March 2008


Temperature dependence of the effective anisotropies in magnetic nanoparticles with Néel surface anisotropy
journal, November 2010


Pulse-noise approach for classical spin systems
journal, January 2017


Surface and step magnetic anisotropy
journal, June 1994


Uniaxial Magnetic Anisotropy in Nanostructured C o / C u ( 001 ) : From Surface Ripples to Nanowires
journal, October 2003


Effects of surface anisotropy on hysteresis in fine magnetic particles
journal, August 1994


Magnetic characterization of iron nanocubes
journal, November 2008

  • Trunova, Anastasia V.; Meckenstock, R.; Barsukov, I.
  • Journal of Applied Physics, Vol. 104, Issue 9
  • DOI: 10.1063/1.3005985

Surface Contribution to the Anisotropy of Magnetic Nanoparticles
journal, February 2003


Effective anisotropies and energy barriers of magnetic nanoparticles with Néel surface anisotropy
journal, August 2007


Numerical evaluation of energy barriers in nano-sized magnetic elements with Lagrange multiplier technique
journal, February 2008


Surface-induced cubic anisotropy in nanomagnets
journal, June 2006


Influence de la résonance paramagnétique sur l'effet Faraday ; discussion d un exemple
journal, January 1954


Microscopic Origin of Magnetic Anisotropy in Au/Co/Au Probed with X-Ray Magnetic Circular Dichroism
journal, November 1995


Surface anisotropy in ferromagnetic nanoparticles
journal, January 2002

  • Labaye, Y.; Crisan, O.; Berger, L.
  • Journal of Applied Physics, Vol. 91, Issue 10
  • DOI: 10.1063/1.1456419

Surface effects on the magnetic properties of ultrafine cobalt particles
journal, February 1998


Thermal and surface anisotropy effects on the magnetization reversal of a nanocluster
journal, June 2008


Reversal time of the magnetization of single-domain ferromagnetic particles with mixed uniaxial and cubic anisotropy
journal, February 2009

  • Coffey, William T.; Déjardin, Pierre-Michel; Kalmykov, Yuri P.
  • Physical Review B, Vol. 79, Issue 5
  • DOI: 10.1103/PhysRevB.79.054401

Enhancement of the magnetic anisotropy of nanometer-sized Co clusters: Influence of the surface and of interparticle interactions
journal, February 2002