Qiu, X.P, Yang, D.Z, Zhou, S.M, Chantrell, R., O'Grady, K., Nowak, U., ...
For polycrystalline NiFe/FeMn bilayers, we have observed and quantified the rotation of the pinning direction in the exchange bias training and recovery effects. During consecutive hysteresis loops,...
Qiu, X. P., Yang, D. Z., Zhou, S. M., Chantrell, R., O'Grady, K, Nowak, U, ...
For ferromagnet/antiferromagnet bilayers, rotation of the easy axis has been \textit{for the first time} observed during measurements of training effect and the recovery of exchange bias using...
Magnetic properties of FePt nanoparticles annealed with NaCl (2006)
Jones, B.A., Dutson, J.D., O'Grady, K., Hickey, B.J., Li, D., Poudyal, N., ...
FePt nanoparticles have the potential to extend the data density of magnetic recording beyond 1 Tbit/in(2). The phase transformation from low anisotropy, face-centered cubic to face-centered...
The role of interfaces in CoFe/IrMn exchange biased systems (2006)
Vallejo-Fernandez, G., Vopsaroiu, M., Fernandez-Outon, L.E., O'Grady, K.
A trilayer system consisting of an IrMn layer exchanged coupled to two CoFe layers of equal thickness has been studied. A single stage reversal was observed over a wide range of temperatures. Two...
Magnetic properties of FePt nanoparticles annealed with NaCl (2006)
Jones, B.A., Dutson, J.D., O'Grady, K., Hickey, B.J., Li, D., Poudyal, N., ...
FePt nanoparticles have the potential to extend the data density of magnetic recording beyond 1 Tbit/in(2). The phase transformation from low anisotropy, face-centered cubic to face-centered...
The role of interfaces in CoFe/IrMn exchange biased systems (2006)
Vallejo-Fernandez, G., Vopsaroiu, M., Fernandez-Outon, L.E., O'Grady, K.
A trilayer system consisting of an IrMn layer exchanged coupled to two CoFe layers of equal thickness has been studied. A single stage reversal was observed over a wide range of temperatures. Two...
Magnetic properties of FePt nanoparticles annealed with NaCl (2006)
Jones, B.A., Dutson, J.D., O'Grady, K., Hickey, B.J., Li, D., Poudyal, N., ...
FePt nanoparticles have the potential to extend the data density of magnetic recording beyond 1 Tbit/in(2). The phase transformation from low anisotropy, face-centered cubic to face-centered...
The role of interfaces in CoFe/IrMn exchange biased systems (2006)
Vallejo-Fernandez, G., Vopsaroiu, M., Fernandez-Outon, L.E., O'Grady, K.
A trilayer system consisting of an IrMn layer exchanged coupled to two CoFe layers of equal thickness has been studied. A single stage reversal was observed over a wide range of temperatures. Two...
Growth rate effects in soft CoFe films (2005)
Vopsaroiu, M., O'Grady, K., Georgieva, M.T., Grundy, P.J., Thwaites, M.J.
We report on growth rate effects in sputter-deposited CoFe films prepared using high target utilization sputtering technology (HiTUS). We find that the grain structure of these polycrystalline films...
Growth rate effects in soft CoFe films (2005)
Vopsaroiu, M., O'Grady, K., Georgieva, M.T., Grundy, P.J., Thwaites, M.J.
We report on growth rate effects in sputter-deposited CoFe films prepared using high target utilization sputtering technology (HiTUS). We find that the grain structure of these polycrystalline films...
Growth rate effects in soft CoFe films (2005)
Vopsaroiu, M., O'Grady, K., Georgieva, M.T., Grundy, P.J., Thwaites, M.J.
We report on growth rate effects in sputter-deposited CoFe films prepared using high target utilization sputtering technology (HiTUS). We find that the grain structure of these polycrystalline films...
Time dependence in perpendicular media with a soft underlayer (2004)
Dutson, J.D., Wu, J., O'Grady, K., Woolsey, N.C., Kubota, Y., Platt, C.L.
In this paper we describe measurements of magnetic viscosity or time dependence in magnetic thin films suitable for use as perpendicular recording media. Generally, such effects cannot be measured...
Novel sputtering-technology for grain-size control (2004)
Vopsaroiu, M., Thwaites, M.J., Rand, S., Grundy, P.J., O'Grady, K.
In this paper, we present a description of a novel high-rate plasma sputtering system that allows the control of grain size in sputtered films. Additionally, the system has the advantage of a better...
Novel sputtering-technology for grain-size control (2004)
Vopsaroiu, M., Thwaites, M.J., Rand, S., Grundy, P.J., O'Grady, K.
In this paper, we present a description of a novel high-rate plasma sputtering system that allows the control of grain size in sputtered films. Additionally, the system has the advantage of a better...
Time dependence in perpendicular media with a soft underlayer (2004)
Dutson, J.D., Wu, J., O'Grady, K., Woolsey, N.C., Kubota, Y., Platt, C.L.
In this paper we describe measurements of magnetic viscosity or time dependence in magnetic thin films suitable for use as perpendicular recording media. Generally, such effects cannot be measured...
Novel sputtering-technology for grain-size control (2004)
Vopsaroiu, M., Thwaites, M.J., Rand, S., Grundy, P.J., O'Grady, K.
In this paper, we present a description of a novel high-rate plasma sputtering system that allows the control of grain size in sputtered films. Additionally, the system has the advantage of a better...
Time dependence in perpendicular media with a soft underlayer (2004)
Dutson, J.D., Wu, J., O'Grady, K., Woolsey, N.C., Kubota, Y., Platt, C.L.
In this paper we describe measurements of magnetic viscosity or time dependence in magnetic thin films suitable for use as perpendicular recording media. Generally, such effects cannot be measured...
Novel sputtering-technology for grain-size control (2004)
Vopsaroiu, M., Thwaites, M.J., Rand, S., Grundy, P.J., O'Grady, K.
In this paper, we present a description of a novel high-rate plasma sputtering system that allows the control of grain size in sputtered films. Additionally, the system has the advantage of a better...
Determination of activation volumes of reversal in perpendicular media (2003)
Dutson, J.D., O'Grady, K., Lu, B., Kubota, Y., Platt, C.L.
We discuss a method for the determination of activation volumes of reversal in perpendicular media. This method does not require correction for the self-demagnetizing field normally associated with...
Determination of activation volumes of reversal in perpendicular media (2003)
Dutson, J.D., O'Grady, K., Lu, B., Kubota, Y., Platt, C.L.
We discuss a method for the determination of activation volumes of reversal in perpendicular media. This method does not require correction for the self-demagnetizing field normally associated with...
Determination of activation volumes of reversal in perpendicular media (2003)
Dutson, J.D., O'Grady, K., Lu, B., Kubota, Y., Platt, C.L.
We discuss a method for the determination of activation volumes of reversal in perpendicular media. This method does not require correction for the self-demagnetizing field normally associated with...
O'Grady, K., Holloway, L., Antel, W.J.
The value of exchange field of two FeMn–NiFeCobased spin valves with varying thickness of the pinned ferromagnetic layer has been determined as a function of temperature. The complexities caused by...
Thermally activated reversal in exchange-coupled structures (2002)
Wang, Y.G., Petford-Long, A.K., Laidler, H., O'Grady, K., Kief, M.T.
In this paper, we study the thermally activated reversal of IrMn/CoFe exchange-coupled structures using Lorentz microscopy and magnetometry. An asymmetry and a training effect were found on the...
Magnetization reversal in AFC media (2002)
Wu, J., Dutson, J., O'Grady, K.
In this paper, we report on a study of magnetization reversal processes in antiferromagnetically coupled media. We describe the reversal in terms of the reversible and irreversible susceptibility...
O'Grady, K., Holloway, L., Antel, W.J.
The value of exchange field of two FeMn–NiFeCobased spin valves with varying thickness of the pinned ferromagnetic layer has been determined as a function of temperature. The complexities caused by...
Thermally activated reversal in exchange-coupled structures (2002)
Wang, Y.G., Petford-Long, A.K., Laidler, H., O'Grady, K., Kief, M.T.
In this paper, we study the thermally activated reversal of IrMn/CoFe exchange-coupled structures using Lorentz microscopy and magnetometry. An asymmetry and a training effect were found on the...
Magnetization reversal in AFC media (2002)
Wu, J., Dutson, J., O'Grady, K.
In this paper, we report on a study of magnetization reversal processes in antiferromagnetically coupled media. We describe the reversal in terms of the reversible and irreversible susceptibility...
O'Grady, K., Holloway, L., Antel, W.J.
The value of exchange field of two FeMn–NiFeCobased spin valves with varying thickness of the pinned ferromagnetic layer has been determined as a function of temperature. The complexities caused by...
Thermally activated reversal in exchange-coupled structures (2002)
Wang, Y.G., Petford-Long, A.K., Laidler, H., O'Grady, K., Kief, M.T.
In this paper, we study the thermally activated reversal of IrMn/CoFe exchange-coupled structures using Lorentz microscopy and magnetometry. An asymmetry and a training effect were found on the...
Magnetization reversal in AFC media (2002)
Wu, J., Dutson, J., O'Grady, K.
In this paper, we report on a study of magnetization reversal processes in antiferromagnetically coupled media. We describe the reversal in terms of the reversible and irreversible susceptibility...
Magnetic characterization of perpendicular recording media (2002)
Wu, J., Holloway, L., Laidler, H., O'Grady, K., Khizroev, S., Howard, J.K., ...
In this paper, we describe techniques for the magnetic characterization of perpendicular recording media. Such measurements made using traditional techniques, such as the vibrating sample...
Magnetic characterization of perpendicular recording media (2002)
Wu, J., Holloway, L., Laidler, H., O'Grady, K., Khizroev, S., Howard, J.K., ...
In this paper, we describe techniques for the magnetic characterization of perpendicular recording media. Such measurements made using traditional techniques, such as the vibrating sample...
Magnetic characterization of perpendicular recording media (2002)
Wu, J., Holloway, L., Laidler, H., O'Grady, K., Khizroev, S., Howard, J.K., ...
In this paper, we describe techniques for the magnetic characterization of perpendicular recording media. Such measurements made using traditional techniques, such as the vibrating sample...
An investigation of time-dependent domain wall pinning effects in Tb/Fe multilayer thin films (2002)
Popplewell,J., O'Grady,K., Llewellyn,J. P., Davies,P.
Magnetic materials consisting of ferrofluids and ferrofluid composites i.e. mixtures of ferrofluid with metallic tin or non-metallic polystyrene or glass particles (0.2 micron to 25 micron diameter)...
The oxidation and magnetic properties of MP recording media particles (2000)
MP recording media pigments have been subjected to elevated temperatures of 180(C in air at various rates of heating from room temperature. It has been found that the rate of heating of these...
The oxidation and magnetic properties of MP recording media particles (2000)
MP recording media pigments have been subjected to elevated temperatures of 180(C in air at various rates of heating from room temperature. It has been found that the rate of heating of these...
The oxidation and magnetic properties of MP recording media particles (2000)
MP recording media pigments have been subjected to elevated temperatures of 180(C in air at various rates of heating from room temperature. It has been found that the rate of heating of these...
Frequency-dependent susceptibility measurements of environmental materials. (1996)
Dearing, J. A., Dann, R. J. L., Hay, K., Lees, J. A., Loveland, P. J., Maher, Barbara A., ...
The theory, measurement and interpretation of frequency-dependent susceptibility (Xfd) are examined. A new model is proposed which explains Xfd in terms of the behaviour of all superparamagnetic...
X-ray and neutron scattering studies of laser-annealed Tb-Fe-Co thin films (1990)
Haycock, P W, Stirling, W G, Gould, R D, Tang, C C, Jones, D L, Herdman, G J, ...
Structural and magnetic properties of laser-annealed magneto-optic thin films (1990)
Haycock, P W, Noyau, R H, Thomson, T, Herdman, G J, Williams, E W, O'Grady, K
MAGNETIC VISCOSITY EFFECTS IN DIGITAL RECORDING MEDIA (1988)
Uren, S., O'Grady, K., Chantrell, R.
We study the relationship between the coefficient of magnetic viscosity (S = -dĪ/d ln t) and the switching field distribution (S.F.D.) for a magnetic recording tape. The SFD can be measured as...
MEASUREMENT OF MAGNETIC TEXTURE IN COBALT-PHOSPHORUS THIN FILMS (1988)
In this work we report on a range of magnetic studies of cobalt-phosphorus thin films prepared by electroless deposition. From these measurements we have derived the distribution of easy axes within...
PARTICLE INTERACTION EFFECTS IN FERROFLUIDS (1988)
Ayoub, N., Abu-Aisheh, B., Laham, N., Dababneh, M., Popplewell, J., O'Grady, K.
An analysis of particle interactions in a magnetite ferrofluid has enabled an interpretation to be made of a nonlinear variation of initial susceptibility with concentration, Curie Weiss behaviour...
SUSCEPTIBILITY PEAKS IN A FINE PARTICLE SYSTEM (1988)
El-Hilo, M., O'Grady, K., Popplewell, J., Chantrell, R., Ayoub, N.
From measurements of the peaks in the dc susceptibility with concentration, for a system of Fe3O4 particles, we have obtained a simple power-law relationship between Tg (temperature at χmax) and...
THE ISOTHERMAL REMANENCE OF FINE PARTICLE SYSTEMS (1988)
Walker, M., Chantrell, R., O'Grady, K., Charles, S.
A numerical model based upon the "Stoner-Wohlfarth theory" has been developed to predict Isothermal Remanent Magnetisation (IRM) curves for a system of fine particles with uniaxial anisotropy. This...
MAGNETIC VISCOSITY EFFECTS IN DIGITAL RECORDING MEDIA (1988)
Uren, S., O'Grady, K., Chantrell, R.
We study the relationship between the coefficient of magnetic viscosity (S = -dĪ/d ln t) and the switching field distribution (S.F.D.) for a magnetic recording tape. The SFD can be measured as...
MEASUREMENT OF MAGNETIC TEXTURE IN COBALT-PHOSPHORUS THIN FILMS (1988)
In this work we report on a range of magnetic studies of cobalt-phosphorus thin films prepared by electroless deposition. From these measurements we have derived the distribution of easy axes within...
PARTICLE INTERACTION EFFECTS IN FERROFLUIDS (1988)
Ayoub, N., Abu-Aisheh, B., Laham, N., Dababneh, M., Popplewell, J., O'Grady, K.
An analysis of particle interactions in a magnetite ferrofluid has enabled an interpretation to be made of a nonlinear variation of initial susceptibility with concentration, Curie Weiss behaviour...
SUSCEPTIBILITY PEAKS IN A FINE PARTICLE SYSTEM (1988)
El-Hilo, M., O'Grady, K., Popplewell, J., Chantrell, R., Ayoub, N.
From measurements of the peaks in the dc susceptibility with concentration, for a system of Fe3O4 particles, we have obtained a simple power-law relationship between Tg (temperature at χmax) and...
THE ISOTHERMAL REMANENCE OF FINE PARTICLE SYSTEMS (1988)
Walker, M., Chantrell, R., O'Grady, K., Charles, S.
A numerical model based upon the "Stoner-Wohlfarth theory" has been developed to predict Isothermal Remanent Magnetisation (IRM) curves for a system of fine particles with uniaxial anisotropy. This...
MAGNETIC VISCOSITY EFFECTS IN DIGITAL RECORDING MEDIA (1988)
Uren, S., O'Grady, K., Chantrell, R.
We study the relationship between the coefficient of magnetic viscosity (S = -dĪ/d ln t) and the switching field distribution (S.F.D.) for a magnetic recording tape. The SFD can be measured as...
MEASUREMENT OF MAGNETIC TEXTURE IN COBALT-PHOSPHORUS THIN FILMS (1988)
In this work we report on a range of magnetic studies of cobalt-phosphorus thin films prepared by electroless deposition. From these measurements we have derived the distribution of easy axes within...
PARTICLE INTERACTION EFFECTS IN FERROFLUIDS (1988)
Ayoub, N., Abu-Aisheh, B., Laham, N., Dababneh, M., Popplewell, J., O'Grady, K.
An analysis of particle interactions in a magnetite ferrofluid has enabled an interpretation to be made of a nonlinear variation of initial susceptibility with concentration, Curie Weiss behaviour...
SUSCEPTIBILITY PEAKS IN A FINE PARTICLE SYSTEM (1988)
El-Hilo, M., O'Grady, K., Popplewell, J., Chantrell, R., Ayoub, N.
From measurements of the peaks in the dc susceptibility with concentration, for a system of Fe3O4 particles, we have obtained a simple power-law relationship between Tg (temperature at χmax) and...
THE ISOTHERMAL REMANENCE OF FINE PARTICLE SYSTEMS (1988)
Walker, M., Chantrell, R., O'Grady, K., Charles, S.
A numerical model based upon the "Stoner-Wohlfarth theory" has been developed to predict Isothermal Remanent Magnetisation (IRM) curves for a system of fine particles with uniaxial anisotropy. This...
THE MAGNETIC PROPERTIES OF A FERROFLUID WITH DIPOLAR INTERACTIONS (1985)
Bradbury, A., Menear, S., Chantrell, R., O'Grady, K.
A model of the properties of a ferrofluid containing weakly interacting particles is presented. The model is based on the Monte-Carlo method, and is used to study the effects of interactions on the...
THE MAGNETIC PROPERTIES OF A FERROFLUID WITH DIPOLAR INTERACTIONS (1985)
Bradbury, A., Menear, S., Chantrell, R., O'Grady, K.
A model of the properties of a ferrofluid containing weakly interacting particles is presented. The model is based on the Monte-Carlo method, and is used to study the effects of interactions on the...
THE MAGNETIC PROPERTIES OF A FERROFLUID WITH DIPOLAR INTERACTIONS (1985)
Bradbury, A., Menear, S., Chantrell, R., O'Grady, K.
A model of the properties of a ferrofluid containing weakly interacting particles is presented. The model is based on the Monte-Carlo method, and is used to study the effects of interactions on the...