Effective anisotropy field in the free layer of patterned spin-valve resistors

2011 ◽  
Vol 109 (10) ◽  
pp. 103904 ◽  
Author(s):  
Zhenghong Qian ◽  
Ru Bai ◽  
Changmao Yang ◽  
Qiliang Li ◽  
Yucheng Sun ◽  
...  
Keyword(s):  
Spin Valve ◽  
Anisotropy Field ◽  
Free Layer ◽  
Effective Anisotropy

High-sensitive hysteresisless spin valve with a composite free layer

2012 ◽  
Vol 113 (4) ◽  
pp. 341-348 ◽  
Author(s):  
V. V. Ustinov ◽  
M. A. Milyaev ◽  
L. I. Naumova ◽  
V. V. Proglyado ◽  
N. S. Bannikova ◽  
...  
Keyword(s):  
Spin Valve ◽  
Free Layer

Effect of Thickness on Mechanically Tunable Magnetic Anisotropy of FeGa Thin Films Deposited on Flexible Substrates

2015 ◽  
Vol 815 ◽  
pp. 227-232 ◽  
Author(s):  
Ying Yu ◽  
Shu Hong Xie ◽  
Qing Feng Zhan
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Effective Strain ◽  
Anisotropy Field ◽  
Saturation Field ◽  
Effective Anisotropy ◽  
Magnetostriction Constant ◽  
The Difference ◽  
Different Strains

A practical way to manipulate the magnetic anisotropy of magnetostrictive FeGa thin films grown on flexible polyethylene terephthalate (PET) substrates is introduced in this study. The effect of film thickness on magnetic properties and magnetostriction constant of polycrystalline FeGa thin films was investigated. The anisotropy field Hk of flexible FeGa films, i.e., the saturation field determined by fitting the hysteresis curves measured along the hard axis, was enhanced with increasing the tensile strain applied along the easy axis of the thin films, but this enhancement via strain became unconspicuous with increasing the thickness of FeGa films. In order to study the magnetic sensitivity of thin films responding to the external stress, we applied different strains on these films and measure the corresponding anisotropy field. Moreover, the effective magnetostriction constant of FeGa films was calculated from the changes of both anisotropy field and external strain based on the Villari effect. A Neel’s phenomenological model was developed to illustrate that the effective anisotropy field of FeGa thin films was contributed from both the constant volume term and the inverse thickness dependent surface term. Therefore, the magnetic properties for the volume and surface of FeGa thin films were different, which has been verified in this work by using vibrating sample magnetometer (VSM) and magneto-optic Kerr effect (MOKE) system. The anisotropy field contributed by the surface of FeGa film and obtained by MOKE is smaller than that contributed by the film volume and measured by VSM. We ascribed the difference in Hk to the relaxation of the effective strain applied on the films with increasing the thickness of films.

scholarly journals Noise Characterization of Vortex-State GMR Sensors with Different Free Layer Thicknesses

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1013
Author(s):  
Herbert Weitensfelder ◽  
Hubert Brueckl ◽  
Armin Satz ◽  
Dieter Suess
Keyword(s):  
Spin Valve ◽  
Low Frequency ◽  
Vortex State ◽  
Frequency Noise ◽  
Free Layer ◽  
Low Frequencies ◽  
Gmr Sensors ◽  
Noise Characterization ◽  
Higher Sensitivity

The spin valve principle is the most prominent sensor design among giant- (GMR) and tunneling (TMR) magnetoresistive sensors. A new sensor concept with a disk shaped free layer enables the formation of a flux-closed vortex magnetization state if a certain relation of thickness to diameter is given. The low frequency noise of current-in-plane GMR sensing elements with different free layer thicknesses at different external field strengths has been measured. The measurements of the 1/f noise in external fields enabled a separation of magnetic and electric noise contributions. It has been shown that while the sensitivity is increasing with a decreasing element thickness, the pink noise contribution is increasing too. Still the detection limit at low frequencies is better in thinner free layer elements due to the higher sensitivity.

Before- and after-domain rotation of the free layer of an FeMn based spin valve

1999 ◽  
Vol 198-199 ◽  
pp. 73-75 ◽  
Author(s):  
J.H. Lee ◽  
B.K. Park ◽  
K. Rhie ◽  
G. Choe ◽  
K.H. Shin
Keyword(s):  
Spin Valve ◽  
Free Layer ◽  
Before And After ◽  
Domain Rotation
Sign in / Sign up

Export Citation Format

Share Document