FN ISI Export Format
VR 1.0
PT J
AU Hardner, HT
   Huben, MJ
   Tabat, N
TI Noise and magnetic domain fluctuations in spin-valve GMR heads
SO IEEE TRANSACTIONS ON MAGNETICS
AB Random telegraph noise (RTN) can be observed in the voltage
   across some spin valve heads over particular ranges of bias
   current, magnetic field and temperature. The detailed
   dependence of the RTN signal on these parameters demonstrates
   that the noise is due to thermally activated magnetic domain
   fluctuations. Further, a comparison of the effects of applied
   magnetic field and bias current provides information about the
   physical location of the magnetic domains within the head.
BP 2592
EP 2594
PG 3
JI IEEE Trans. Magn.
PY 1999
PD SEP
VL 35
IS 5
PN 1
GA 246EH
J9 IEEE TRANS MAGN
UT ISI:000083151100120
ER

PT J
AU van de Veerdonk, RJM
   Belien, PJL
   Schep, KM
   Kools, JCS
   de Nooijer, MC
   Gijs, MAM
   Coehoom, R
   de Jonge, WJM
TI 1/f noise in anisotropic and giant magnetoresistive elements
SO JOURNAL OF APPLIED PHYSICS
AB Microfabricated magnetoresistive elements based on either the
   anisotropic or the giant magnetoresistance effect were tested
   for their frequency dependent resistance noise behavior at room
   temperature in a de magnetic field, using a de sense current.
   Thermal resistance noise was the dominant noise source above
   about 10 kHz, At low frequencies the resistance noise was found
   to be dominated by a 1/f contribution that depends on the
   applied magnetic field. The 1/f noise is relatively low and
   field independent when the element is in a saturated state and
   contains a relatively large and field dependent excess
   contribution when the magnetic field is in the sensitive field
   range of the element. The 1/f noise level observed in
   saturation is comparable to the 1/f noise level found in
   nonmagnetic metals; the excess noise has a magnetic origin. The
   variation of the excess noise level with the applied de
   magnetic field can be explained qualitatively using a simple
   model based on thermal excitations of the magnetization
   direction, (C) 1997 American Institute of Physics.
BP 6152
EP 6164
PG 13
JI J. Appl. Phys.
PY 1997
PD DEC 15
VL 82
IS 12
GA YM236
J9 J APPL PHYS
UT ISI:000071043400040
ER

PT J
AU Rogers, CT
   Kirschenbaum, LS
   Beale, PD
   Russek, SE
   Sanders, SC
TI Observation of a fluctuation-enhanced magnetoresistance in
   Ni81F19/Ag multilayers at high current density
SO PHYSICAL REVIEW B-CONDENSED MATTER
AB We report a correlation between peaks observed in the
   resistance versus applied magnetic field and low-frequency
   resistance noise for Ni81Fe19/Ag giant magnetoresistance
   systems with de bias current density above 10(6) A/cm(2). The
   magnetic noise has a 1/f-like spectrum and arises from time-
   dependent magnetic orientational fluctuations within the
   multilayer. The noise amplitude is strongly correlated with the
   observed magnetoresistance peaks. The data and a simple model
   for the fluctuations demonstrate the important role of
   fluctuations in determining magnetoresistance in such
   multilayer systems.
BP R8503
EP R8506
PG 4
JI Phys. Rev. B-Condens Matter
PY 1997
PD OCT 1
VL 56
IS 14
GA YC731
J9 PHYS REV B-CONDENSED MATTER
UT ISI:A1997YC73100013
ER

PT J
AU Wan, H
   Bohlinger, MM
   Jenson, M
   Hurst, A
TI Comparison of flicker noise in single layer, AMR and GMR
   sandwich magnetic film devices
SO IEEE TRANSACTIONS ON MAGNETICS
AB Flicker noise comparison has been made on single layer NiFeCo,
   Sandwich AMR NiFeCo/TaN/NiFeCo and GMR
   NiFeCo/CoFe/Cu/CoFe/NiFeCo films. In a single magnetic domain
   state, AMR films have noise close to the thermal noise, GMR has
   2-3 times higher noise, and in a state having a useful MR
   ratio, the GMR film has 10 times higher noise than AMR sandwich
   film, while the sandwich film has 10 times higher noise than
   single layer AMR film.
BP 3409
EP 3411
PG 3
JI IEEE Trans. Magn.
PY 1997
PD SEP
VL 33
IS 5
PN 1
GA XW564
J9 IEEE TRANS MAGN
UT ISI:A1997XW56400261
ER

PT J
AU Persat, N
   vandenBerg, HAM
   Dinia, A
TI Domain-phase transformations in antiferromagnetically coupled
   Co/Cu sandwiches
SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
AB A new type of domain-phase conversion is demonstrated in
   perfect antiferromagnetically coupled multilayers. The magnetic
   transformations occurring in polycrystalline Co/Cu/Co
   sandwiches, exhibiting hardly any coupling defects, have been
   evidenced by investigating the giant magnetoresistive response
   along minor loops. The following hypothesis is given for the
   origin of the transformations. High domain density state,
   originating in the freedom of the sense of the rotation of the
   magnetization, occurs when coming from saturation. The domain
   conversions remain fully reversible above a certain threshold
   field value. Below this value some domains start to vanish as a
   consequence of the instabilities that arise from the existence
   of domain walls with large wall angles. This irreversible
   process leads to the formation of a new magnetic state,
   consisting of large domains, where the domain conversions are
   fully reversible inside a certain field window.
BP 446
EP 449
PG 4
JI J. Magn. Magn. Mater.
PY 1997
PD JAN
VL 165
IS 1-3
GA WF862
J9 J MAGN MAGN MATER
UT ISI:A1997WF86200114
ER

PT J
AU Weissman, MB
TI Low-frequency noise as a tool to study disordered materials
SO ANNUAL REVIEW OF MATERIALS SCIENCE
AB The use of noise to determine the properties of defects in
   crystalline matter and the types of dynamical coherence in
   various glassy structures is described. Some introduction is
   given to traditional and new analysis tools, especially ones
   using non-Gaussian statistics. Many examples are provided in
   glasses, metals with defects, spin glasses, charge-density
   waves, disordered domain structures, magnetic vortices in
   superconductors, and related areas. The focus is on quasi-
   equilibrium effects, but driven noise, e.g. the Barkhausen
   effect, is also discussed. The examples range from testing
   theories of the spin-glass state to in situ testing of the
   stress in steel cables.
BP 395
EP 429
PG 35
JI Annu. Rev. Mater. Sci.
PY 1996
VL 26
GA VB465
J9 ANNU REV MATER SCI
UT ISI:A1996VB46500016
ER

PT J
AU Hardner, HT
   Weissman, MB
   Miller, B
   Loloee, R
   Parkin, SSP
TI Resistance noise in uncoupled giant magnetoresistive
   multilayers
SO JOURNAL OF APPLIED PHYSICS
AB Various uncoupled, magnetoresistive multilayer systems show
   quasiequilibrium resistance noise associated with \dr(H)/dH\.
   The size of this 1/f noise, particularly in comparison with
   Johnson noise in various frequency ranges, is discussed for all
   the different systems. All the observed samples exhibit
   resistive Barkhausen noise, allowing the measurement of domain
   sizes very similar to those observed in coupled samples. In
   addition, the asymmetric hysteresis of the Barkhausen noise in
   uncoupled multilayers suggests the same type of hysteretic
   domain structure observed in antiferromagnetically coupled
   multilayers. (C) 1996 American Institute of Physics.
BP 7751
EP 7756
PG 6
JI J. Appl. Phys.
PY 1996
PD MAY 15
VL 79
IS 10
GA UK226
J9 J APPL PHYS
UT ISI:A1996UK22600044
ER