Determination of f0 for fine magnetic particles

D. P E Dickson; N. M K Reid; C. Hunt; H. D. Williams; M. El-Hilo; K. O'Grady

doi:10.1016/0304-8853(93)90109-F

Determination of f₀ for fine magnetic particles

D. P E Dickson, N. M K Reid, C. Hunt, H. D. Williams, M. El-Hilo^*, K. O'Grady

^*Corresponding author for this work

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

Abstract

In this paper we have determined a value for the pre-exponential factor in the Néel-Arhennius equation for the iron oxyhydroxide particles found in the protein ferritin. The data were obtained using a combination of zero field magnetic and Mössbauer spectroscopy studies yielding a value for f₀ of (9.5±2.7)X10¹¹ Hz. This value is significantly different to that of 2.8 X 10⁹ Hz commonly used and in closer agreement to that of 10¹³ Hz obtained for iron particles using an analogous technique. Using our experimental value for f₀ gives a revised superparamagnetic criterion for DC magnetic measurements on a 100 second time-scale of KV < 32 kT and a Mössbauer spectroscopy criterion for a measurement time-scale of 10^-9 s of KV < 8 kT. Our results together with other published data would suggest that a more appropriate estimate for the value of f₀ would lie in the range 10¹² to 10¹³ Hz.

Original language	English
Pages (from-to)	345-350
Number of pages	6
Journal	Journal of Magnetism and Magnetic Materials
Volume	125
Issue number	3
DOIs	https://doi.org/10.1016/0304-8853(93)90109-F
Publication status	Published - 1993

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10.1016/0304-8853(93)90109-F

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title = "Determination of f0 for fine magnetic particles",

abstract = "In this paper we have determined a value for the pre-exponential factor in the N{\'e}el-Arhennius equation for the iron oxyhydroxide particles found in the protein ferritin. The data were obtained using a combination of zero field magnetic and M{\"o}ssbauer spectroscopy studies yielding a value for f0 of (9.5±2.7)X1011 Hz. This value is significantly different to that of 2.8 X 109 Hz commonly used and in closer agreement to that of 1013 Hz obtained for iron particles using an analogous technique. Using our experimental value for f0 gives a revised superparamagnetic criterion for DC magnetic measurements on a 100 second time-scale of KV < 32 kT and a M{\"o}ssbauer spectroscopy criterion for a measurement time-scale of 10-9 s of KV < 8 kT. Our results together with other published data would suggest that a more appropriate estimate for the value of f0 would lie in the range 1012 to 1013 Hz.",

author = "Dickson, {D. P E} and Reid, {N. M K} and C. Hunt and Williams, {H. D.} and M. El-Hilo and K. O'Grady",

year = "1993",

doi = "10.1016/0304-8853(93)90109-F",

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volume = "125",

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journal = "Journal of Magnetism and Magnetic Materials",

issn = "0304-8853",

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TY - JOUR

T1 - Determination of f0 for fine magnetic particles

AU - Dickson, D. P E

AU - Reid, N. M K

AU - Hunt, C.

AU - Williams, H. D.

AU - El-Hilo, M.

AU - O'Grady, K.

PY - 1993

Y1 - 1993

N2 - In this paper we have determined a value for the pre-exponential factor in the Néel-Arhennius equation for the iron oxyhydroxide particles found in the protein ferritin. The data were obtained using a combination of zero field magnetic and Mössbauer spectroscopy studies yielding a value for f0 of (9.5±2.7)X1011 Hz. This value is significantly different to that of 2.8 X 109 Hz commonly used and in closer agreement to that of 1013 Hz obtained for iron particles using an analogous technique. Using our experimental value for f0 gives a revised superparamagnetic criterion for DC magnetic measurements on a 100 second time-scale of KV < 32 kT and a Mössbauer spectroscopy criterion for a measurement time-scale of 10-9 s of KV < 8 kT. Our results together with other published data would suggest that a more appropriate estimate for the value of f0 would lie in the range 1012 to 1013 Hz.

AB - In this paper we have determined a value for the pre-exponential factor in the Néel-Arhennius equation for the iron oxyhydroxide particles found in the protein ferritin. The data were obtained using a combination of zero field magnetic and Mössbauer spectroscopy studies yielding a value for f0 of (9.5±2.7)X1011 Hz. This value is significantly different to that of 2.8 X 109 Hz commonly used and in closer agreement to that of 1013 Hz obtained for iron particles using an analogous technique. Using our experimental value for f0 gives a revised superparamagnetic criterion for DC magnetic measurements on a 100 second time-scale of KV < 32 kT and a Mössbauer spectroscopy criterion for a measurement time-scale of 10-9 s of KV < 8 kT. Our results together with other published data would suggest that a more appropriate estimate for the value of f0 would lie in the range 1012 to 1013 Hz.

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U2 - 10.1016/0304-8853(93)90109-F

DO - 10.1016/0304-8853(93)90109-F

M3 - Article

AN - SCOPUS:0027641133

SN - 0304-8853

VL - 125

SP - 345

EP - 350

JO - Journal of Magnetism and Magnetic Materials

JF - Journal of Magnetism and Magnetic Materials

IS - 3

ER -

Determination of f0 for fine magnetic particles

Abstract

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Determination of f₀ for fine magnetic particles