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#3
((Fe/Ag) or (Fe/Au)) and (antiferromagnetic coupling)
28
#2
(Fe) and (antiferromagnetic coupling) and ((Ag) or (Au))
59
#1
(Fe) and (antiferromagnetic coupling)
495
Results of: ((Fe/Ag) or (Fe/Au)) and (antiferromagnetic coupling)
Record 1 of 28 in INSPEC 1996
Giant magnetoresistance in evaporated Ni-Fe/Cu and Ni-Fe-Co/Cu multilayers
Zeltser-AM; Smith-N
Journal-of-Applied-Physics. vol.79, no.12; 15 June 1996; p.9224-30
1996
English
The magnetic and transport properties of electron-beam evaporated (Ni/sub 83/Fe/sub 17//Cu)/sub 10/ and (Ni/sub 66/Fe/sub 16/Co/sub 18//Cu)/sub 10/ multilayers were studied as a function of the Cu spacer, magnetic layer and Ta buffer layer thicknesses, as well as annealing conditions. All multilayers exhibited very small giant magnetoresistance (GMR) effect (<0.3%) in the as-deposited state, however, after magnetic post-annealing at 300-325 degrees C, GMR increased up to 4.5%-7%, depending on the multilayer type. In contrast to sputtered Ni-Fe-(Co)/Cu multilayers, GMR showed no oscillatory behavior as a function of Cu thickness. Similar to that reported in sputtered "discontinuous"
Ni-Fe
/
Ag
multilayers, it is believed that Cu diffusion along the Ni-Fe-(Co) grain boundaries creates intra-layer magnetic discontinuities in Ni-Fe-(Co) layers which promote inter-layer
antiferromagnetic
coupling
. The evaporated Ni-Fe/Cu multilayers exhibited very low remanence, exceptionally low hysteresis, and quite uniform GMR properties through the thickness of the multilayer. All of these makes them potentially attractive for application to future magnetoresistive reproduce heads for very high areal density magnetic storage systems.
5338474
Record 2 of 28 in INSPEC 1980-1984
Magnetization measurements for AuFe spin-glass alloys in fields up to 40 T
Smit-JJ; Nieuwenhuys-GJ; de-Jongh-LJ
Solid-State-Communications. vol.32, no.3; Oct. 1979; p.233-8
1979
English
High-field magnetization curves are presented for AuFe alloys of Fe concentrations: c=3.1, 5.1, 6.5 and 10.4 at.%, at T=4.2K in pulsed fields up to 40 T. For c=10.4 at.% additional data were taken at T=1.2K and 77K. From these results the authors conclude that the nearest-neighbour interaction between the Fe atoms in Au is ferromagnetic, of order of 80K. The behaviour of the magnetization curves can be qualitatively explained in terms of ferromagnetic clusters that are antiferromagnetically coupled.
1451032
Record 3 of 28 in INSPEC 1985-1989
Layered magnetic structures: evidence for
antiferromagnetic
coupling
of Fe layers across Cr interlayers
Grunberg-P; Schreiber-R; Pang-Y; Brodsky-MB; Sowers-H
Physical-Review-Letters. vol.57, no.19; 10 Nov. 1986; p.2442-5
1986
English
The authors investigated exchange coupling of Fe layers across Au and Cr interlayers by means of light scattering from spin waves. For Au interlayers they find a continuous decrease of this coupling to zero as the Au thickness is increased from 0 to approximately=20 AA. For Cr interlayers of proper thickness they find
antiferromagnetic
coupling
of the Fe layers. In small external fields such double layers order antiparallel with their magnetization perpendicular to the external field, in analogy to the spin-flop phase of antiferromagnets.
2821306
Record 4 of 28 in INSPEC 1990-1992
Exchange of Fe layers across interlayers with good match
Fuss-A; Wolf-JA; Grunberg-PA
Physica-Scripta-Volume-T. vol.T45; 1992; p.95-8
1992
English
The exchange interaction of Fe across interlayers X, X=Cr, Au, Ag and Al has been investigated by means of M(H) curves and lightscattering from spin waves. For these investigations Fe/X/Fe structures were grown with as good epitaxy and crystallinity as possible, which is documented by in situ RHEED investigations. For this coupling across Cr and Au the authors find oscillations as a function of the interlayer thickness with a long and a short period. For Al interlayers only long periods can be clearly resolved and for Ag no oscillations have been observed. Apart from the oscillations between ferro- and antiferromagnetic type coupling they find also contributions of 90 degrees type coupling which aligns the magnetic films perpendicular to each other. The temperature dependence of 90 degrees coupling has been investigated in the case of Au interlayers.
4284493
Record 5 of 28 in INSPEC 1990-1992
Interlayer exchange, magnetotransport and magnetic domains in Fe/Cr layered structures
Grunberg-P; Demokritov-S; Fuss-A; Schreiber-R; Wolf-JA; Purcell-ST
Journal-of-Magnetism-and-Magnetic-Materials. vol.104-107, pt.3; Feb. 1992; p.1734-8
1992
English
The exchange coupling of Fe across Cr oscillates as a function of the Cr-thickness with a short and a long period. The short-period oscillations are only observed in samples with very good quality. In addition to ferro- and antiferromagnetic type coupling there is also a contribution favouring a perpendicular magnetization alignment of neighbouring magnetic films. Similar effects as for the Fe/Cr system and the authors find also for
Fe
/
Au
and Fe/Al. For the
Fe
/
Ag
system AF type coupling could not be established. The effect of the various types of coupling on magnetic domains has been studied in the Fe/Cr system. An analysis of the new magnetoresistance effect due to antiparallel alignment revealed that for the Fe/Cr system it is due to a spin-dependent electron scattering at the Fe-Cr interfaces. Values for the scattering rates have been obtained.
4181001
Record 6 of 28 in INSPEC 1990-1992
Short- and long period oscillations in the exchange coupling of Fe across epitaxially grown Al- and Au-interlayers
Fub-A; Demokritov-S; Grunberg-P; Zinn-W
Journal-of-Magnetism-and-Magnetic-Materials. vol.103, no.3; Jan. 1992; p.L221-7
1992
English
The authors have investigated the exchange coupling of Fe films across Al- and Au-interlayers with good epitaxial growth. For the first time coupling across Al was found to be antiferromagnetic (a.f.). In addition to the long period oscillations of the coupling now well known from many other systems there are short period oscillations which are clearly visible for Au and faintly visible also for Al. This observation can be correlated with the much better growth of Au interlayers. In both cases the authors find also a strong contribution of biquadratic coupling, previously identified for the Fe/Cr system. The results strongly support an RKKY-type mechanism as the microscopic origin of these couplings.
4114979
Record 7 of 28 in INSPEC 1990-1992
Exchange coupling in Fe/Cu, Pd, Ag,
Au
/
Fe
trilayers
Celinski-Z; Heinrich-B
Journal-of-Magnetism-and-Magnetic-Materials. vol.99, no.1-3; Sept. 1991; p.L25-30
1991
English
Epitaxial trilayer Fe/Cu, Pd, Ag,
Au
/
Fe
structures have been grown by MBE. The growth of BCC Fe(001), Cu(001), lattice expanded FCC Pd(001) and FCC Ag(001) and Au(001) layers were monitored and characterized by RHEED patterns and RHEED intensity oscillations. Ferromagnetic resonance (FMR) and surface magneto-optical Kerr effect (SMOKE) were used to investigate the exchange coupling in these trilayers using a wide range of Cu, Pd, Ag and Au interlayer thicknesses. It is shown that Cu and Pd interlayers exhibit long range
antiferromagnetic
coupling
. Both interlayers exhibit unique oscillatory behavior. The exchange coupling through BCC Cu exhibits only one crossover to
antiferromagnetic
coupling
. The strength of the
antiferromagnetic
coupling
reveals an oscillatory behavior with periodicity of 10 monolayers. In the region of ferromagnetic coupling the exchange coupling through lattice expanded FCC Pd shows an oscillatory behavior with periodicity of 4 monolayers. Ag(001) interlayers show a rapid decrease in the ferromagnetic coupling with increasing Ag interlayer thickness. Au(001) interlayers behave similarly to those of Ag(001). However a weak
antiferromagnetic
coupling
was observed in Au(001).
4042104
Record 8 of 28 in INSPEC 1990-1992
Ferromagnetic resonance of exchange-coupled
Fe
/
Au
/
Fe
trilayers
Yamazaki-H; Ajiro-Y; Hosoito-N; Shinjo-T
Journal-of-the-Physical-Society-of-Japan. vol.60, no.3; March 1991; p.764-7
1991
English
A series of evaporated Fe(30 AA)/Au(d AA)/Fe(10 AA) trilayers with various Au interlayer thicknesses from 10 to 120 AA is investigated by means of ferromagnetic resonance (FMR) technique at 300 K. Exchange coupling between Fe layers accounts for the change of FMR spectra. Comparison of the calculated and the observed resonance field values yields a coupling parameter J as a function of d. For d<or=18 AA, the exchange coupling is strongly ferromagnetic.
Antiferromagnetic
coupling
is realized for 75<d<85 AA.
3912370
Record 9 of 28 in INSPEC 1993-1994
Hot electron spin-valve effect in coupled magnetic layers
Celotta-RJ; Unguris-J; Pierce-DT
Journal-of-Applied-Physics. vol.75, no.10, pt.2B; 15 May 1994; p.6452-4
1994
English
SEMPA observations of magnetic exchange coupling in the
Fe
/
Ag
/
Fe
,
Fe
/
Au
/
Fe
, and Fe/Cr/Fe systems reveal an intensity variation in the emitted secondary electron signal that depends only on whether the Fe layers are coupled in a ferromagnetic or antiferromagnetic sense. We ascribe this new effect to spin dependence in the transport of electrons between the two magnetic layers.
4747612
Record 10 of 28 in INSPEC 1993-1994
Oscillatory exchange coupling in
Fe
/
Au
/
Fe
(100)
Unguris-J; Celotta-RJ; Pierce-DT
Journal-of-Applied-Physics. vol.75, no.10, pt.2B; 15 May 1994; p.6437-9
1994
English
Scanning electron microscopy with polarization analysis was used to investigate the interlayer exchange coupling in
Fe
/
Au
/
Fe
(100) sandwich structures. The films were epitaxially grown on single-crystal Fe(100) substrates. Electron diffraction measurements revealed that the Au spacer film grew with a surface reconstruction consistent with that observed for bulk Au crystals. The exchange coupling oscillates between primarily ferromagnetic and
antiferromagnetic
coupling
for Au spacer layers up to 65 layers (13 nm) thick, but a significant biquadratic coupling component was also observed. The oscillatory coupling exhibited two components with periods of 2.48+or-0.05 layers (0.506+or-0.010 nm) and 8.6+or-0.3 layers (1.75+or-0.06 nm). The measured periods are in excellent agreement with those calculated from spanning vectors of the Au Fermi surface.
4747607
Record 11 of 28 in INSPEC 1993-1994
Domain analysis in epitaxial iron-aluminum and iron-gold sandwiches with oscillatory exchange
McCord-J; Hubert-A; Schafer-R; Fuss-A; Grunberg-P
IEEE-Transactions-on-Magnetics. vol.29, no.6, pt.1; Nov. 1993; p.2735-7
1993
English
Epitaxially grown iron-iron sandwiches with wedge-shaped gold and aluminum interlayers are investigated by Kerr microscopy. While in the
Fe-Au-Fe
sample an oscillatory exchange (which appears, however, of a rather weak and irregular nature) interaction is confirmed, only one transition from ferromagnetic to 90 degrees -coupling is found in the Fe-Al-Fe sample. For Al thickness >15 AA, the domains assume an irregular character, indicating an essentially uncoupled nature. This finding is confirmed by a new technique based on the magnetooptical Voigt effect observed at perpendicular incidence.
4671288
Record 12 of 28 in INSPEC 1993-1994
Quantum-well and tight-binding analyses of spin-polarized photoemission from
Ag
/
Fe
(001) overlayers
Smith-NV; Brookes-NB; Chang-Y; Johnson-PD
Physical-Review-B-(Condensed-Matter). vol.49, no.1; 1 Jan. 1994; p.332-8
1994
English
Spin-polarized photoemission experiments on epitaxial Ag overlayers on Fe(001) have shown that a minority-spin surface state of the bare substrates evolves into an interface state, moves to higher energies, and crosses the Fermi level E/sub F/ between 3 and 4 Ag monolayers. Application of a phase accumulation model shows that this state is a quantum-well (QW) state characterized by the quantum number nu =1, where nu =m-n, and where n and m are the number of wave-function nodes and number of layers, respectively. Higher members of the QW series cross E/sub F/ with a periodicity Delta m=(1-k/sub F//k/sub BZ/)/sup -1/ identical with that in recent theories for the alternation between ferromagnetic and
antiferromagnetic
coupling
in magnetic multilayers. The QW model fails at low coverages. A tight-binding model captures the behavior at low coverages while reproducing QW behavior at high coverages.
4623812
Record 13 of 28 in INSPEC 1993-1994
d-like quantum-well states in (111)-oriented metallic overlayers on Fe and Co
Hartmann-D; Weber-W; Rampe-A; Popovic-S; Guntherodt-G
Physical-Review-B-(Condensed-Matter). vol.48, no.22; 1 Dec. 1993; p.16837-40
1993
English
(111)-oriented metallic overlayers of Cu,Au,Pd, and Pt with thicknesses up to 3 atomic layers (AL) on Fe(110) or Co(0001) show evidence for d-like quantum-well (QW) states in spin-resolved photoemission spectroscopy. The noble-metal d-like QW states are not spin polarized and are well below the Fermi level. In contrast, the d-like QW states of Pd and Pt approach the Fermi level for about 3 AL, but are spin polarized only for the first AL. Thus both types of QW states do not mediate the antiferromagnetic interlayer exchange coupling in corresponding (111)-oriented magnetic multilayers.
4601228
Record 14 of 28 in INSPEC 1993-1994
Oscillatory magnetic coupling in
Fe
/
Ag
/
Fe
(100) sandwich structures
Unguris-J; Celotta-RJ; Pierce-DT
Journal-of-Magnetism-and-Magnetic-Materials. vol.127, no.1-2; Oct. 1993; p.205-13
1993
English
The magnetic coupling in
Fe
/
Ag
/
Fe
sandwich structures has been studied using scanning electron microscopy with polarization analysis (SEMPA), When atomically well-ordered Ag spacer layers are grown epitaxially on an Fe whisker substrate, the coupling between the Fe substrate and the top Fe film is found to oscillate between ferromagnetic and antiferromagnetic as a periodic function of the Ag thickness. The magnetic coupling is composed of two oscillatory components with periods of 2.37+or-0.07 and 5.73+or-0.05 Ag layers. The oscillations persist for Ag spacer films that are up to at least 50 layers thick. These periods are consistent with theoretical models that predict that the oscillatory coupling length scale is determined by spanning vectors of the spacer material's Fermi surface. Biquadratic coupling was also observed in these structures. The relative strength of biquadratic to bilinear coupling was found to depend on the thickness of the top Fe film.
4550370
Record 15 of 28 in INSPEC 1993-1994
Biquadratic exchange coupling in Fe/Cr/Fe(100) and
Fe
/
Ag
/
Fe
(100) thin film sandwiches
Unquris-J; Celotta-RJ; Pierce-DT; Stroscio-JA
Journal-of-Applied-Physics. vol.73, no.10, pt.2A; 15 May 1993; p.5984
1993
English
Summary form only given, as follows. The authors have investigated the magnetic exchange coupling between an Fe film and an Fe(100) single crystal whisker substrate separated by varying thickness Cr or Ag spacer layers. The magnetization of the Fe was measured using scanning electron microscopy with polarization analysis. Reflection high-energy electron diffraction and scanning tunneling microscopy (STM) were used to analyze the film structure. In addition to the oscillatory thickness-dependent bilinear exchange coupling, biquadratic exchange coupling was observed in bot films. At spacer thicknesses that correspond to the transitions between ferromagnetic and
antiferromagnetic
coupling
the Fe film magnetization was in-plane and orthogonal to the ferromagnetic alignment. Their observations generally agree with the model proposed by Slonczewski (1991), in which the biquadratic coupling originates from the bilinear coupling through spatial fluctuations of the spacer thickness. If these fluctuations occur over small enough length scales and the bilinear coupling varies between ferromagnetic and antiferromagnetic with monolayer thickness changes, then the Fe film intralayer exchange stiffness forces biquadratic coupling of the film to the substrate. They have observed the necessary short-period coupling in both Fe/Cr/Fe and
Fe
/
Ag
/
Fe
and have measured the length scale of the thickness variations on a similar sample using a STM. One unexpected result in
Fe
/
Ag
/
Fe
was that the amount of biquadratic coupling increased with increasing top Fe layer thickness. No similar dependence was observed for Fe/Cr/Fe.
4475773
Record 16 of 28 in INSPEC 1993-1994
Magnetoresistance effect and interlayer exchange coupling in epitaxial
Fe
/
Au
(100) and
Fe
/
Au
(111) multilayers
Shintaku-K; Daitoh-Y; Shinjo-T
Physical-Review-B-(Condensed-Matter). vol.47, no.21; 1 June 1993; p.14584-7
1993
English
Single-crystal-like
Fe
/
Au
(100) and polycrystalline
Fe
/
Au
(111) multilayers were prepared by ultrahigh-vacuum deposition. In the
Fe
/
Au
(100) system, a distinct oscillation in the magnetoresistance (MR) ratio in accordance with the changes of interlayer exchange coupling was observed at room temperature as a function of Au-spacer-layer thickness. In the
Fe
/
Au
(111) system, an
antiferromagnetic
coupling
was also confirmed. Flatness of interfaces and well-controlled spacer-layer thicknesses are crucial factors to ensure observation of the MR-oscillation effect.
4466941
Record 17 of 28 in INSPEC 1993-1994
MBE growth of Fe(211)/Au(110) multilayers on MgO(110) substrates
Marty-A; Gilles-B; Eymery-J; Chamberod-A; Joud-JC
Journal-of-Magnetism-and-Magnetic-Materials. vol.121, no.1-3; March 1993; p.57-9
1993
English
A 0.9 nm-Fe(211)/3.1 nm-Au(110) superlattice has been grown and measured by SQUID magnetometry. The magnetization has been found in the plane and the easy direction is (011) due to tension strain along the (111) axis. A weak
antiferromagnetic
coupling
across the Au layers (0.01 erg/cm/sup 2/) has been deduced.
4439753
Record 18 of 28 in INSPEC 1995
Experiments on interlayer exchange coupling
Schaefer-M; Leng-Q; Schreiber-R; Takanashi-K; Gruenberg-P; Zinn-W
Materials-Science-&-Engineering-B-(Solid-State-Materials-for-Advanced-Technology). vol.B31, no.1-2; April 1995; p.17-23
1995
English
Since the discovery of antiferromagnetic (1AF)1 interlayer coupling in 1986, numerous systems have been investigated. Generally, it is found that the coupling of ferromagnetic (1F)1 films separated by an interlayer oscillates as a function of the interlayer thickness between F and AF type and the transition zones are characterized by 90 degrees -type coupling. The oscillation periods are in agreement with a theory that attributes the microscopic origin of the coupling to an indirect exchange of the F layers via the electrons of the interlayer. For the 90 degrees -type coupling, various mechanisms have been proposed, but the situation is still unclear. We present here a condensed overview of the field and communicate some of our recent results.
5048342
Record 19 of 28 in INSPEC 1995
Layer thickness and temperature variation of the giant magnetoresistance in
Fe
/
Ag
multilayers
Shuxiang-Li; Chengtao-Yu; Wuyan-Lai; Yizhong-Wang; Minglang-Yan
Journal-of-Applied-Physics. vol.78, no.1; 1 July 1995; p.405-8
1995
English
The magnetoresistance ratio in
Fe
/
Ag
multilayers is increased dramatically with decreasing Fe layer thickness. This behavior can be explained in terms of interference of electronic Bloch waves due to interface roughness and lattice mismatch between Fe and Ag layers. At the same time, the interlayer coupling changes from ferromagnetic to antiferromagnetic when the Fe layer thickness is decreased. An anomalous temperature effect of magnetoresistance is also observed. The magnetoresistance ratio at 4.2 K is smaller than that at 300 K when the Fe layer thickness is larger than about 12 AA, which can be attributed to the presence of some superparamagnetic-like thin pieces at the interfaces.
5013345
Record 20 of 28 in INSPEC 1995
Biquadratic coupling in
Fe
/
Au
/
Fe
trilayers: experimental evidence for the magnetic-dipole mechanism
Rucker-U; Demokritov-S; Tsymbal-E; Grunberg-P; Zinn-W
Journal-of-Applied-Physics. vol.78, no.1; 1 July 1995; p.387-91
1995
English
We have compared the biquadratic coupling in epitaxially grown
Fe
/
Au
/
Fe
(100)-systems with different interface roughness. The profound short-period oscillations observed on the smooth samples are found to be wiped out for the sample with rougher interfaces. In addition, a stronger biquadratic coupling has been observed. For all measured Au-interlayer thicknesses (1.3-2.4 nm) the biquadratic coupling dominates the antiferromagnetic and ferromagnetic coupling, in contrast to the measurements of the samples with smooth interfaces. The observed increase in biquadratic coupling can be explained in the frame of the currently proposed magnetic-dipole mechanism. The experimental results are in a good agreement with the calculation based on this mechanism, which used the roughness parameters obtained by scanning tunneling microscopy and which did not need any fitting parameters. Thus the existence of the magnetic-dipole coupling mechanism has been confirmed experimentally.
5013342
Record 21 of 28 in INSPEC 1995
Structure and magnetism of epitaxially strained Pd(001) films on Fe(001): experiment and theory
Fullerton-EE; Stoeffler-D; Ounadjela-K; Heinrich-B; Celinski-Z; Bland-JAC
Physical-Review-B-(Condensed-Matter). vol.51, no.10; 1 March 1995; p.6364-78
1995
English
We present an experimental and theoretical description of the structure and magnetism of epitaxially strained Pd(001) films on Fe(001) and in Fe/Pd/Fe(001) trilayers. The structure is determined by combining reflection high-energy electron diffraction and X-ray diffraction. For
Fe
/
Au
(001) bilayers and Fe/Pd/Au(001) trilayers grown by molecular-beam epitaxy on Ag(001), the Fe and Au layers are well represented by their bulk structure, whereas, thin Pd layers have a face-centered tetragonal structure with an in-plane expansion of 4.2% and an out-of-plane contraction of 7.2% (c/a=0.89). Theoretical ab initio studies of the interfacial structure indicate that the structural ground state of the epitaxially strained Pd layer is well described by a fct structure which maintains the bulk Pd atomic volume with small deviations at the interface. For Fe/Pd/Fe trilayers, the interlayer coupling oscillates with a period of 4 monolayers (ML) on a ferromagnetic background that crosses to weak
antiferromagnetic
coupling
for thicknesses >12 ML of Pd. Strong ferromagnetic coupling observed below 5 ML of Pd indicates that 2 ML of Pd at each interface are ferromagnetically ordered. Theoretical studies of Fe/sub 3/Pd/sub n/ superlattices (where n is the number of Pd atomic layers) determine the polarization of the Pd layer and the interlayer magnetic coupling to depend strongly on the c/a ratio of the Pd layers. Modeling of a Pd layer with a constant-volume fct structure and one monolayer interfacial roughness find that the first 2 ML of the Pd is polarized in close agreement with the experimental results. Polarized neutron reflectivity results on an Fe(5.6 ML)/Pd(7 ML)/Au(20 ML) sample determine the average moment per Fe atom of 2.66+or-0.05 mu /sub B/. Calculations for the same structure show that this value is consistent with the induced Pd polarization.
4938114
Record 22 of 28 in INSPEC 1995
Giant magnetoresistance in
Fe
/
Ag
multilayer
Yu-Cheng-Tao; Li-Shu-Xiang; Yan-Ming-Lang; Ku-Wan-Jun; Yin-Lin; Wang-Yi-Zhong; Lai-Wu-Yan; Wang-Zhen-Xi
Chinese-Science-Bulletin. vol.39, no.20; Oct. 1994; p.1680-3
1994
English
The observation of a giant magnetoresistance in an
Fe
/
Ag
multilayer is presented for the first time. It has been found that the GMR oscillates with variation of the Ag thickness and the oscillation period is about 1.1 nm.
4867768
Record 23 of 28 in INSPEC 1/97-6/97
Optimization of giant magnetoresistance in ion beam sputtered Co/Cu multilayers
Schmeusser-S; Rupp-G; Hubert-A
Journal-of-Magnetism-and-Magnetic-Materials. vol.166, no.3; Feb. 1997; p.267-76
1997
English
Ion beam sputtering (IBS) was used to prepare Co/Cu multilayer films within the first
antiferromagnetic
coupling
range. Several preparation conditions were varied to optimize the giant magnetoresistance effect. We report the improvement of magnetoresistance by changing the sputtering gas from Ar to Xe, by finding an optimal substrate position and ion beam acceleration voltage, and by increasing the growth rate. A maximum magnetoresistance of 51 was achieved at room temperature in a stack with only 16 periods. The obtained improvements compared to previous efforts are discussed in terms of interface sharpness, layer homogeneity, and impurity incorporation. The main advantage of the established plasma sputtering technique, which still yields somewhat better results compared to IBS, appears to he a larger growth rate resulting in less impurity incorporation.
5543221
Record 24 of 28 in INSPEC 1/97-6/97
Magnetism of nanoscale fcc-Fe clusters in Cu and Ag matrices
Li-Zhiqiang; Kawazoe-Y; Hashi-Y
Materials-Science-&-Engineering-A-(Structural-Materials:-Properties,-Microstructure-and-Processing). vol.217-218; 30 Oct. 1996; p.299-302
1996
English
The magnetic and electronic properties of fcc-Fe clusters embedded in both Cu and Ag matrices are studied by the first-principles spin-polarized calculations within the local density functional formalism. Single Fe atoms in Cu and Ag hosts are found to have magnetic moments of 3.05 mu /sub B/ and 3.31 mu /sub B/, respectively. Small Fe/sub n/ clusters (n<or=13) in Cu exhibit high-moment ferromagnetic coupling, while larger clusters (n>or=13) in Cu show low-moment
antiferromagnetic
coupling
. The Fe clusters in the Ag host exhibit only high-moment ferromagnetic behavior. The magnetic properties of embedded fcc-Fe clusters in Cu have some features in common with the nanoscale fcc Fe/Cu(100) films.
5524341
Record 25 of 28 in INSPEC 7/97-12/97
Magnetic properties and giant magnetoresistance of
Fe
/
Au
multilayers
Honda-S; Koguma-K; Nawate-M; Sakamoto-I
Journal-of-Applied-Physics. vol.82, no.9; 1 Nov. 1997; p.4428-34
1997
English
Magnetic properties and magnetoresistance (MR) are examined for the
Fe
/
Au
multilayers (MLs) prepared on glass substrates by electron-beam evaporation techniques as a function of the thicknesses of Fe and Au layers; d/sub Fe/ and d/sub Au/. For small d/sub Fe/, the perpendicular magnetic anisotropy is induced, and in the films of d/sub Fe/ approximately=5 AA, the stripe magnetic domain patterns are observed. In d/sub Fe/<or=3 AA, however, a superparamagnetic nature and a granular-type giant magnetoresistance (GMR) appear at room temperature. In a series of [Fe(3 AA)/Au(d/sub Au/)]/sub 40/ MLs, the MR ratio increases with d/sub Au/ and reaches the first peak at around 10 AA. On the other hand, at 14 K, the ferromagnetic component having a perpendicular anisotropy becomes dominant, and the GMR arises from the random wall alignment due to the
antiferromagnetic
coupling
between the adjacent Fe layers, causing the first MR peak at d/sub Au/ approximately=10 AA. The layered structure is obscured and the superparamagnetic Fe grains are created by annealing at 300-350 degrees C, followed by the crystalline growth upon annealing at temperatures above 350 degrees C. These variations in the film morphology cause the changes in the saturation magnetization and the MR ratio.
5748772
Record 26 of 28 in INSPEC 7/97-12/97
Structural and magnetic properties of Fe/Cr and
Fe
/
Ag
multilayers
Temst-K; Verbanck-G; Schad-R; Gladyszewski-G; Hennion-M
Physica-B. vol.234-236; June 1997; p.467-9
1997
English
The structural and magnetic properties of Fe/Cr and
Fe
/
Ag
magnetic superlattices are discussed. The presence of
antiferromagnetic
coupling
in Fe/Cr superlattices was clearly established, whereas
Fe
/
Ag
superlattices do not show
antiferromagnetic
coupling
in their as-prepared state. Thermal annealing and ion irradiation lead to an increase of the magnetoresistance due to the formation of a granular
Fe-Ag
alloy and a Kondo system, respectively.
5688809
Record 27 of 28 in INSPEC 1998/01-1998/06
Lattice strain in magnetic ultrathin films
McManus-MK; Crozier-ED; Jiang-DT; Heinrich-B
Journal-de-Physique-IV-(Colloque). vol.7, no.C2, pt.2; April 1997; p.683-5
1997
English
A clear understanding of the mechanisms of interfacial magnetic anisotropy rests on the structural characterisation of magnetic multilayers which, typically, consist of two ferromagnetically coupled (F) layers separated by a non-magnetic spacer layer. Fe/Cu/Fe trilayers are of special interest since the coupling between the F layers of Fe changes from F to antiferromagnetic depending on the thickness of the Cu spacer layer. Here, a magnetic multilayer system, grown by molecular beam epitaxy (MBE), was modified by inserting Cr in the Cu: Ag(001)/8.7 Fe/3 Cu/6 Cr/3 Cu/5 Fe/10 Au where the integers refer to monolayers. Polarized K-edge XAFS spectra (E parallel to the substrate) were obtained from fluorescence measurements in the total reflection geometry. The multiple scattering paths were analysed for the Cr edge. The initial Cu grew pseudomorphically in a BCC structure on
Fe
/
Ag
(001). The Cr proved to be tetragonally distorted from its BCC structure. The overlayers of Fe on Cu are contracted by 1.27% within the plane and conserve the c lattice parameter of Fe, though the atomic volume is contracted by 2.8%. The Cu adopts a BCT, rather than keeping its bulk FCC, structure and the corresponding decrease in its atomic volume from the FCC is only 0.3%.
5875492
Record 28 of 28 in INSPEC 1999/01-1999/10
Interlayer coupling of Fe/Si/Fe trilayers with very thin boundary layers
Endo-Y; Kitakami-O; Shimada-Y
Journal-of-Applied-Physics. vol.85, no.8; 15 April 1999; p.5741-3
1999
English
The interlayer magnetic coupling of a Fe/Si/Fe trilayer shows an analogous feature to that of Fe/Si superlattices. With an increase in Si layer thickness, it oscillates as ferromagnetic (first F), antiferromagnetic (AF), ferromagnetic (second F), and finally reaches a noncoupling (N) state. We have investigated interlayer coupling of Fe/Si/Fe trilayers inserting very thin (1 or 2 ML thick) boundary layers X (X=Ag, Ge, Fe-Si, Ta, etc.). They are expected to suppress interatomic diffusion between Fe and Si layers. Interlayer coupling of Fe/X/Si/X/Fe with negligible interdiffusion is simply F and changes to N as the Si layer thickness increases. Furthermore, Fe/Fe-Si/Fe trilayers which show coupling of first F, AF but not second F, reproduce second F when a Si layer is inserted in the Fe-Si spacer. These results imply that an amorphous Si spacer mediates ferromagnetic coupling between neighboring Fe layers while the first F and the strong AF coupling usually observed in Fe/Si superlattices are caused by diffused crystalline Fe-Si.
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