P. Holody - Academia.edu (original) (raw)
Papers by P. Holody
Physical Review Letters, 1994
The resistivity of magnetic multilayers is generally smaller when the magnetizations of successiv... more The resistivity of magnetic multilayers is generally smaller when the magnetizations of successive layers are parallel, which is the so-called giant magnetoresistance or spin-valve effect. %'e have been able to reverse this eA'ect and to obtain a smaller resistivity for an antiparallel arrangement by intercalating thin Cr layers within half of the Fe layers in Fe/Cu multilayers. This inverse spin-valve elfect is due to the inverse spin asymmetries of the electron scattering in successive Fe layers with and without Cr. This is a confirmation of the fundamental mechanism of the giant magnetoresistance.
For ferromagnetic(F)/noble metal(N) multilayers in which the spin-diffusion length ls >> th... more For ferromagnetic(F)/noble metal(N) multilayers in which the spin-diffusion length ls >> the F/N unit cell thickness, the two spin-current model predicts that the quantity, &surd;R^AP(R^AP-R^P) (where R^AP and R^P are CPP resistances of the antiparallel and parallel states), varies linearly with the number of bilayers with a slope independent of rho_N. If ls becomes <= N-layer thickness, there are deviations
Journal of Applied Physics
ABSTRACT
7th Joint MMM-Intermag Conference. Abstracts (Cat. No.98CH36275), 1998
Physical Review B, 1997
We have fabricated Co/Al2O3/Co tunnel junctions in which the Al2O3 layer includes a unique layer ... more We have fabricated Co/Al2O3/Co tunnel junctions in which the Al2O3 layer includes a unique layer of small and disconnected cobalt clusters, with a typical mean diameter ranging from 2.0 to 4.0 nm. We observe spin-dependent tunneling properties with, below about 50 K, typical Coulomb-blockade effects induced by intermediate electron tunneling into cobalt clusters. The tunnel magnetoresistance ratio is approximately the
Physical Review B, 2002
We have studied the electric and magnetotransport properties of Co//Al2O3/CoI/Al2O3//(Co or Cu) t... more We have studied the electric and magnetotransport properties of Co//Al2O3/CoI/Al2O3//(Co or Cu) tunnel double junctions, in which the intermediate CoI layer is either granular or percolated clusters and the top electrode is either Co or Cu. In granular junctions, spin-dependent tunneling with Coulomb-blockade effect was observed. The temperature dependence of the resistance can be attributed to two conduction channels in
MRS Proceedings, 1993
ABSTRACTThe Magnetoresistance Measured perpendicular to the plane of the Multilayer, (CPP-MR) has... more ABSTRACTThe Magnetoresistance Measured perpendicular to the plane of the Multilayer, (CPP-MR) has been measured for the Cu/CO and Cu/ (Ni/Fe) systems. The predictions of a two spin-channel model are summarized, and the Cu/CO data are analysed in terms of this theory. The Cu/ (NiFe) data show a more complex behaviour.
Physical review. B, Condensed matter, 1996
... Sud, Bat 510, 91405 Orsay, France P. Holody Department of Physics, Michigan State University,... more ... Sud, Bat 510, 91405 Orsay, France P. Holody Department of Physics, Michigan State University, East Lansing, Michigan 48824 Received 15 December 1995; revised manuscript received 21 February 1996 We present measurements of the angular dependence of the giant ...
Physical review. B, Condensed matter, 1996
Spin-relaxation effects are generally believed to have a strong influence on giant magnetoresista... more Spin-relaxation effects are generally believed to have a strong influence on giant magnetoresistance of ferromagnetic/noble-metal multilayers. We have measured current perpendicular to plane magnetoresistances (CPP MR&#x27;s) of sputtered Co/Cu 1-x Ni x multilayers with x=0.06, 0.10, ...
Physical review. B, Condensed matter, 1995
We show that a simple two-current model gives good predictions of the low-temperature perpendicul... more We show that a simple two-current model gives good predictions of the low-temperature perpendicular (CPP) specific resistances, ARt (A=sample area, Rt=sample resistance), of sputtered Co/Cu/Py/Cu (Py=Ni84Fe16~=permalloy) multilayers with neighboring Co and Py layers in well-defined parallel (P) or antiparallel (AP) magnetic states, using only parameters derived without adjustment from prior measurements on Co/Cu and Py/Cu multilayers.
Physical Review B, 1996
We report measurements of the increase in perpendicular specific resistance (area times total res... more We report measurements of the increase in perpendicular specific resistance (area times total resistance, ARt) of multilayers of two nonmagnetic metals with increasing number of interfaces, when the total amount of each metal is held constant. For multilayers of Ag and Cu, Ag and Au, and Au and Cu sputtered under narrowly defined conditions, we find, per interface, ARAg/Cu=0.044+/-0.003 fOmega
Physical Review Letters, 1994
... Length and Giant Magnetoresistance at Low Temperatures Q. Yang, P. Holody, S.-F. Lee, LLHenry... more ... Length and Giant Magnetoresistance at Low Temperatures Q. Yang, P. Holody, S.-F. Lee, LLHenry, R. Loloee ... [171 It is known that the spin glasses AgMn and CuMn exhibit negative linearMR at high ... a, edited by K.-H. Hellwege and JL Olsen (Springer-Verlag, Berlin, 1982). ...
Physical Review Letters, 1997
From data on \(Fe1-xVx/Cu/Co/Cu\)N multilayers, we show that Fe doped with V gains a negative spi... more From data on \(Fe1-xVx/Cu/Co/Cu\)N multilayers, we show that Fe doped with V gains a negative spin asymmetry for bulk scattering \(beta&amp;amp;lt;0\), which, combined with the positive asymmetry of Co, accounts for the inverse current perpendicular to the plane (CPP) giant magnetoresistance (GMR) we observe. More precisely, the competition between positive and negative asymmetries for interface and bulk scatterings in FeV
physica status solidi (b), 2010
Electron tunneling between two ferromagnetic electrodes across an insulating barrier is analysed ... more Electron tunneling between two ferromagnetic electrodes across an insulating barrier is analysed theoretically and experimentally. The barrier is either uniform or it includes a layer of small magnetic metallic particles. Particular attention is paid to the origin of the tunneling magnetoresistance and its bias dependence, as well as to the effects due to Coulomb blockade.
Physica B: Condensed Matter, 1994
ABSTRACT
Materials Science and Engineering: B, 1995
This chapter contains a brief review of the giant magnetoresistance (GMR) effect exhibited by mag... more This chapter contains a brief review of the giant magnetoresistance (GMR) effect exhibited by magnetic multilayers, granular alloys, and related materials. Subjects covered include a description of the phenomenon, and the related oscillatory interlayer exchange coupling in magnetic multilayers; a simple model of giant magnetoresistance; the inverse GMR effect in spin-engineered magnetic multilayers; structures that display large changes in resistance in small magnetic fields, possibly for use in magnetic field sensors; and the dependence of GMR on various aspects of the magnetic structures.
Materials Science and Engineering: B, 1995
... The agreement is, however, not perfect, in that the ratio of measured to predicted difference... more ... The agreement is, however, not perfect, in that the ratio of measured to predicted differences between AR, for the AP and P states, [ARt(Hap) ARt(H)] [ARAp AR[], aver ... The broken lines are "better fit" adjustments within the uncertainties of some of the CoCu and PyCu parameters ...
Physical Review Letters, 1994
The resistivity of magnetic multilayers is generally smaller when the magnetizations of successiv... more The resistivity of magnetic multilayers is generally smaller when the magnetizations of successive layers are parallel, which is the so-called giant magnetoresistance or spin-valve effect. %'e have been able to reverse this eA'ect and to obtain a smaller resistivity for an antiparallel arrangement by intercalating thin Cr layers within half of the Fe layers in Fe/Cu multilayers. This inverse spin-valve elfect is due to the inverse spin asymmetries of the electron scattering in successive Fe layers with and without Cr. This is a confirmation of the fundamental mechanism of the giant magnetoresistance.
For ferromagnetic(F)/noble metal(N) multilayers in which the spin-diffusion length ls >> th... more For ferromagnetic(F)/noble metal(N) multilayers in which the spin-diffusion length ls >> the F/N unit cell thickness, the two spin-current model predicts that the quantity, &surd;R^AP(R^AP-R^P) (where R^AP and R^P are CPP resistances of the antiparallel and parallel states), varies linearly with the number of bilayers with a slope independent of rho_N. If ls becomes <= N-layer thickness, there are deviations
Journal of Applied Physics
ABSTRACT
7th Joint MMM-Intermag Conference. Abstracts (Cat. No.98CH36275), 1998
Physical Review B, 1997
We have fabricated Co/Al2O3/Co tunnel junctions in which the Al2O3 layer includes a unique layer ... more We have fabricated Co/Al2O3/Co tunnel junctions in which the Al2O3 layer includes a unique layer of small and disconnected cobalt clusters, with a typical mean diameter ranging from 2.0 to 4.0 nm. We observe spin-dependent tunneling properties with, below about 50 K, typical Coulomb-blockade effects induced by intermediate electron tunneling into cobalt clusters. The tunnel magnetoresistance ratio is approximately the
Physical Review B, 2002
We have studied the electric and magnetotransport properties of Co//Al2O3/CoI/Al2O3//(Co or Cu) t... more We have studied the electric and magnetotransport properties of Co//Al2O3/CoI/Al2O3//(Co or Cu) tunnel double junctions, in which the intermediate CoI layer is either granular or percolated clusters and the top electrode is either Co or Cu. In granular junctions, spin-dependent tunneling with Coulomb-blockade effect was observed. The temperature dependence of the resistance can be attributed to two conduction channels in
MRS Proceedings, 1993
ABSTRACTThe Magnetoresistance Measured perpendicular to the plane of the Multilayer, (CPP-MR) has... more ABSTRACTThe Magnetoresistance Measured perpendicular to the plane of the Multilayer, (CPP-MR) has been measured for the Cu/CO and Cu/ (Ni/Fe) systems. The predictions of a two spin-channel model are summarized, and the Cu/CO data are analysed in terms of this theory. The Cu/ (NiFe) data show a more complex behaviour.
Physical review. B, Condensed matter, 1996
... Sud, Bat 510, 91405 Orsay, France P. Holody Department of Physics, Michigan State University,... more ... Sud, Bat 510, 91405 Orsay, France P. Holody Department of Physics, Michigan State University, East Lansing, Michigan 48824 Received 15 December 1995; revised manuscript received 21 February 1996 We present measurements of the angular dependence of the giant ...
Physical review. B, Condensed matter, 1996
Spin-relaxation effects are generally believed to have a strong influence on giant magnetoresista... more Spin-relaxation effects are generally believed to have a strong influence on giant magnetoresistance of ferromagnetic/noble-metal multilayers. We have measured current perpendicular to plane magnetoresistances (CPP MR&#x27;s) of sputtered Co/Cu 1-x Ni x multilayers with x=0.06, 0.10, ...
Physical review. B, Condensed matter, 1995
We show that a simple two-current model gives good predictions of the low-temperature perpendicul... more We show that a simple two-current model gives good predictions of the low-temperature perpendicular (CPP) specific resistances, ARt (A=sample area, Rt=sample resistance), of sputtered Co/Cu/Py/Cu (Py=Ni84Fe16~=permalloy) multilayers with neighboring Co and Py layers in well-defined parallel (P) or antiparallel (AP) magnetic states, using only parameters derived without adjustment from prior measurements on Co/Cu and Py/Cu multilayers.
Physical Review B, 1996
We report measurements of the increase in perpendicular specific resistance (area times total res... more We report measurements of the increase in perpendicular specific resistance (area times total resistance, ARt) of multilayers of two nonmagnetic metals with increasing number of interfaces, when the total amount of each metal is held constant. For multilayers of Ag and Cu, Ag and Au, and Au and Cu sputtered under narrowly defined conditions, we find, per interface, ARAg/Cu=0.044+/-0.003 fOmega
Physical Review Letters, 1994
... Length and Giant Magnetoresistance at Low Temperatures Q. Yang, P. Holody, S.-F. Lee, LLHenry... more ... Length and Giant Magnetoresistance at Low Temperatures Q. Yang, P. Holody, S.-F. Lee, LLHenry, R. Loloee ... [171 It is known that the spin glasses AgMn and CuMn exhibit negative linearMR at high ... a, edited by K.-H. Hellwege and JL Olsen (Springer-Verlag, Berlin, 1982). ...
Physical Review Letters, 1997
From data on \(Fe1-xVx/Cu/Co/Cu\)N multilayers, we show that Fe doped with V gains a negative spi... more From data on \(Fe1-xVx/Cu/Co/Cu\)N multilayers, we show that Fe doped with V gains a negative spin asymmetry for bulk scattering \(beta&amp;amp;lt;0\), which, combined with the positive asymmetry of Co, accounts for the inverse current perpendicular to the plane (CPP) giant magnetoresistance (GMR) we observe. More precisely, the competition between positive and negative asymmetries for interface and bulk scatterings in FeV
physica status solidi (b), 2010
Electron tunneling between two ferromagnetic electrodes across an insulating barrier is analysed ... more Electron tunneling between two ferromagnetic electrodes across an insulating barrier is analysed theoretically and experimentally. The barrier is either uniform or it includes a layer of small magnetic metallic particles. Particular attention is paid to the origin of the tunneling magnetoresistance and its bias dependence, as well as to the effects due to Coulomb blockade.
Physica B: Condensed Matter, 1994
ABSTRACT
Materials Science and Engineering: B, 1995
This chapter contains a brief review of the giant magnetoresistance (GMR) effect exhibited by mag... more This chapter contains a brief review of the giant magnetoresistance (GMR) effect exhibited by magnetic multilayers, granular alloys, and related materials. Subjects covered include a description of the phenomenon, and the related oscillatory interlayer exchange coupling in magnetic multilayers; a simple model of giant magnetoresistance; the inverse GMR effect in spin-engineered magnetic multilayers; structures that display large changes in resistance in small magnetic fields, possibly for use in magnetic field sensors; and the dependence of GMR on various aspects of the magnetic structures.
Materials Science and Engineering: B, 1995
... The agreement is, however, not perfect, in that the ratio of measured to predicted difference... more ... The agreement is, however, not perfect, in that the ratio of measured to predicted differences between AR, for the AP and P states, [ARt(Hap) ARt(H)] [ARAp AR[], aver ... The broken lines are "better fit" adjustments within the uncertainties of some of the CoCu and PyCu parameters ...