Characterizing the magnetic anisotropy constant of spinel cobalt ferrite nanoparticles

Adam J. Rondinone; Anna C.S. Samia; Z. John Zhang

doi:10.1063/1.126727

Characterizing the magnetic anisotropy constant of spinel cobalt ferrite nanoparticles

Adam J. Rondinone
, Anna C.S. Samia
, Z. John Zhang

Research output: Contribution to journal › Article › peer-review

128 Scopus citations

Abstract

Superconducting quantum interference device (SQUID) magnetometry and Mössbauer spectroscopy have been combined to determine the magnetic anisotropy constant K of spinel CoFe₂O₄ nanoparticles. The anisotropy constant is 2.23×10⁶ erg/cm³ for CoFe₂O₄ nanoparticles with a mean diameter of 8.5 nm. A relaxation-time constant of τ₀= 1.90×10^-14s has also been obtained. The magnetic anisotropy distribution function of the nanoparticles has been extracted from the temperature dependence of remanence decay in SQUID measurements. The population percentage of the superparamagnetically relaxed nanoparticles at each temperature can be calculated from this anisotropy distribution function. Such a population calculation from SQUID measurements can also fit the results from Mossbauer spectroscopic measurements even though these two measuring methods are fundamentally distinct. Such a successful fit implies that the anisotropy distribution function from our SQUID measurement is truly an intrinsic feature of the nanoparticles.

Original language	English
Pages (from-to)	3624-3626
Number of pages	3
Journal	Applied Physics Letters
Volume	76
Issue number	24
DOIs	https://doi.org/10.1063/1.126727
State	Published - Jun 12 2000
Externally published	Yes

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title = "Characterizing the magnetic anisotropy constant of spinel cobalt ferrite nanoparticles",

abstract = "Superconducting quantum interference device (SQUID) magnetometry and M{\"o}ssbauer spectroscopy have been combined to determine the magnetic anisotropy constant K of spinel CoFe2O4 nanoparticles. The anisotropy constant is 2.23×106 erg/cm3 for CoFe2O4 nanoparticles with a mean diameter of 8.5 nm. A relaxation-time constant of τ0= 1.90×10-14s has also been obtained. The magnetic anisotropy distribution function of the nanoparticles has been extracted from the temperature dependence of remanence decay in SQUID measurements. The population percentage of the superparamagnetically relaxed nanoparticles at each temperature can be calculated from this anisotropy distribution function. Such a population calculation from SQUID measurements can also fit the results from Mossbauer spectroscopic measurements even though these two measuring methods are fundamentally distinct. Such a successful fit implies that the anisotropy distribution function from our SQUID measurement is truly an intrinsic feature of the nanoparticles.",

author = "Rondinone, \{Adam J.\} and Samia, \{Anna C.S.\} and Zhang, \{Z. John\}",

year = "2000",

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doi = "10.1063/1.126727",

language = "English",

volume = "76",

pages = "3624--3626",

journal = "Applied Physics Letters",

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publisher = "American Institute of Physics",

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TY - JOUR

T1 - Characterizing the magnetic anisotropy constant of spinel cobalt ferrite nanoparticles

AU - Rondinone, Adam J.

AU - Samia, Anna C.S.

AU - Zhang, Z. John

PY - 2000/6/12

Y1 - 2000/6/12

N2 - Superconducting quantum interference device (SQUID) magnetometry and Mössbauer spectroscopy have been combined to determine the magnetic anisotropy constant K of spinel CoFe2O4 nanoparticles. The anisotropy constant is 2.23×106 erg/cm3 for CoFe2O4 nanoparticles with a mean diameter of 8.5 nm. A relaxation-time constant of τ0= 1.90×10-14s has also been obtained. The magnetic anisotropy distribution function of the nanoparticles has been extracted from the temperature dependence of remanence decay in SQUID measurements. The population percentage of the superparamagnetically relaxed nanoparticles at each temperature can be calculated from this anisotropy distribution function. Such a population calculation from SQUID measurements can also fit the results from Mossbauer spectroscopic measurements even though these two measuring methods are fundamentally distinct. Such a successful fit implies that the anisotropy distribution function from our SQUID measurement is truly an intrinsic feature of the nanoparticles.

AB - Superconducting quantum interference device (SQUID) magnetometry and Mössbauer spectroscopy have been combined to determine the magnetic anisotropy constant K of spinel CoFe2O4 nanoparticles. The anisotropy constant is 2.23×106 erg/cm3 for CoFe2O4 nanoparticles with a mean diameter of 8.5 nm. A relaxation-time constant of τ0= 1.90×10-14s has also been obtained. The magnetic anisotropy distribution function of the nanoparticles has been extracted from the temperature dependence of remanence decay in SQUID measurements. The population percentage of the superparamagnetically relaxed nanoparticles at each temperature can be calculated from this anisotropy distribution function. Such a population calculation from SQUID measurements can also fit the results from Mossbauer spectroscopic measurements even though these two measuring methods are fundamentally distinct. Such a successful fit implies that the anisotropy distribution function from our SQUID measurement is truly an intrinsic feature of the nanoparticles.

UR - https://www.scopus.com/pages/publications/0000814323

U2 - 10.1063/1.126727

DO - 10.1063/1.126727

M3 - Article

SN - 0003-6951

VL - 76

SP - 3624

EP - 3626

JO - Applied Physics Letters

JF - Applied Physics Letters

IS - 24

ER -

Characterizing the magnetic anisotropy constant of spinel cobalt ferrite nanoparticles

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