Weak field control of remanent magnetization changes produced by uniaxial stress cycling

1988 ◽  
Vol 15 (5) ◽  
pp. 511-513 ◽  
Author(s):  
M. Lanham ◽  
M. Fuller
Keyword(s):  
Remanent Magnetization ◽  
Uniaxial Stress ◽  
Weak Field ◽  
Field Control ◽  
Stress Cycling

Calculations for Uniaxial Stress and Strain Cycling in Plasticity

1984 ◽  
Vol 51 (3) ◽  
pp. 487-493 ◽  
Author(s):  
P. M. Naghdi ◽  
D. J. Nikkel
Keyword(s):  
Type Theory ◽  
Uniaxial Stress ◽  
Mean Value ◽  
Stress And Strain ◽  
Material Response ◽  
Tension And Compression ◽  
Stress Cycling ◽  
The Mean ◽  
Rate Type ◽  
Strain Cycling

Within the framework of an existing purely mechanical, rate-type theory of plasticity, detailed calculations are presented for certain types of material response during stress and strain cycling in a uniaxial homogeneous deformation. These features pertain specifically to material response in stress cycling between fixed values of stress in tension and compression (not necessarily equal in magnitude) resulting in ratcheting of strain, and a type of saturation hardening caused by strain cycling between any two fixed values of strain when the mean value of stress (in tension and compression) tends to zero.

Single-domain theory for the reversible effect of small uniaxial stress upon the remanent magnetization of rock

1977 ◽  
Vol 14 (9) ◽  
pp. 2047-2061 ◽  
Author(s):  
J. P. Hodych
Keyword(s):  
Remanent Magnetization ◽  
Thermal Activation ◽  
Magnetocrystalline Anisotropy ◽  
Uniaxial Stress ◽  
Titanium Content ◽  
Single Domain ◽  
Stress Axis ◽  
Compression Axis ◽  
Saturation Remanence ◽  
Approximate Expressions

This paper on small uniaxial stress changing the remanent magnetization of rock is a companion to my previous paper on stress changing susceptibility, both phenomena being of current interest in attempts at earthquake forecasting.Theoretical expressions are derived (using rigorous energy-minimization but ignoring thermal activation) for reversible change in remanence parallel to the stress axis for samples containing single-domain grains of a ferromagnet with cubic magnetocrystalline anisotropy (K1 positive or negative) and anisotropic magnetostriction. The grains are assumed to be non-interacting and randomly oriented spheres or ellipsoids of revolution elongated along [Formula: see text], [Formula: see text], or [Formula: see text]. Also, approximate expressions are given for samples containing multidomain grains with very strongly pinned walls. Thermal (or chemical), anhysteretic, and saturation remanence are discussed.For remanence change perpendicular to the stress axis, one expects −1/2 the above expressions for change parallel to the stress axis, which is easily proven for thermal remanence.The expressions predict that for magnetite-bearing rock the decrease in thermal remanence along a 100 bar (1 × 104 kPa) compression axis should be 0.76% for spherical single-domain grains, 0.27% for 1.4 to 1 elongation along [Formula: see text], and 0.09% for great elongation along [Formula: see text]. The decrease for equidimensional multidomain grains with strongly-pinned walls should be ~0.38%. These are all much smaller than the corresponding estimates for susceptibility, but both remanence and susceptibility decreases should become larger and more comparable as titanium content increases.

scholarly journals Control by decoherence: weak field control of an excited state objective

2010 ◽  
Vol 12 (1) ◽  
pp. 015003 ◽  
Author(s):  
Gil Katz ◽  
Mark A Ratner ◽  
Ronnie Kosloff
Keyword(s):  
Excited State ◽  
Weak Field ◽  
Field Control

Grain separation enhanced magnetic coercivity in Pt/Co multilayers.

1993 ◽  
Vol 51 ◽  
pp. 1038-1039 ◽  
Author(s):  
G.A. Bertero ◽  
R. Sinclair
Keyword(s):  
Remanent Magnetization ◽  
Strong Influence ◽  
Uniaxial Anisotropy ◽  
Magnetic Coupling ◽  
Recording Media ◽  
Magnetic Media ◽  
Signal To Noise ◽  
Out Of Plane ◽  
Longitudinal Recording ◽  
The Relationship

Pt/Co multilayers displaying perpendicular (out-of-plane) magnetic anisotropy and 100% perpendicular remanent magnetization are strong candidates as magnetic media for the next generation of magneto-optic recording devices. The magnetic coercivity, Hc, and uniaxial anisotropy energy, Ku, are two important materials parameters, among others, in the quest to achieving higher recording densities with acceptable signal to noise ratios (SNR). The relationship between Ku and Hc in these films is not a simple one since features such as grain boundaries, for example, can have a strong influence on Hc but affect Ku only in a secondary manner. In this regard grain boundary separation provides a way to minimize the grain-to-grain magnetic coupling which is known to result in larger coercivities and improved SNR as has been discussed extensively in the literature for conventional longitudinal recording media.We present here results from the deposition of two Pt/Co/Tb multilayers (A and B) which show significant differences in their coercive fields.

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