Magnetization reversal and anisotropy in CoO/permalloy/Cu/permalloy/NiO layered structures

2001 ◽  
Vol 226-230 ◽  
pp. 1764-1766 ◽  
Author(s):  
C Prados ◽  
E Pina ◽  
P Crespo ◽  
M Alonso-Sañudo ◽  
F Cebollada ◽  
...  
1993 ◽  
Vol 313 ◽  
Author(s):  
B. Heinrich ◽  
Z. Celiński ◽  
H. Konno ◽  
A. S. Arrott ◽  
M. Rührig ◽  
...  

ABSTRACTThe lattice reconstructed bec Ni (001) in Fe/Ni (001) ultrathin layers allows one to engineer films in which the in-plane 4-fold anisotropies and coercive fields can be varied and adjusted according to specific requirements. Magnetization reversals have been studied in layered structures of Fe/Ag/Fe/Ni (001). For Ag (001) interlayers thicker than 13 ML Magnetization reversal can proceed in two steps. In these samples the minor loops switch the magnetization of the Fe (001) layer from the parallel to the antiparallel configurations with respect to the magnetic moment of the Fe/Ni film. Such Minor loops exhibit a rectangular behavior with switching fields of 15–25 Oe. The lattice transformed Fe/Ni layers could be useful in spin-valve structures.


2004 ◽  
Vol 27 (1-3) ◽  
pp. 415-418
Author(s):  
J. Bak-Misiuk ◽  
A. Misiuk ◽  
J. Ratajczak ◽  
A. Shalimov ◽  
I. Antonova ◽  
...  

2020 ◽  
pp. 54-58
Author(s):  
S. M. Plotnikov

The division of the total core losses in the electrical steel of the magnetic circuit into two components – losses dueto hysteresis and eddy currents – is a serious technical problem, the solution of which will effectively design and construct electrical machines with magnetic circuits having low magnetic losses. In this regard, an important parameter is the exponent α, with which the frequency of magnetization reversal is included in the total losses in steel. Theoretically, this indicator can take values from 1 to 2. Most authors take α equal to 1.3, which corresponds to the special case when the eddy current losses are three times higher than the hysteresis losses. In fact, for modern electrical steels, the opposite is true. To refine the index α, an attempt was made to separate the total core losses on the basis that the hysteresis component is proportional to the first degree of the magnetization reversal frequency, and the eddy current component is proportional to the second degree. In the article, the calculation formulas of these components are obtained, containing the values of the total losses measured in idling experiments at two different frequencies, and the ratio of these frequencies. It is shown that the rational frequency ratio is within 1.2. Presented the graphs and expressions to determine the exponent α depending on the measured no-load losses and the frequency of magnetization reversal.


1994 ◽  
Vol 18 (2) ◽  
pp. 193-196 ◽  
Author(s):  
H. Nishio ◽  
H. Taguchi ◽  
F. Hirata ◽  
T. Takeishi

1993 ◽  
Vol 17 (S_1_MORIS_92) ◽  
pp. S1_255-257 ◽  
Author(s):  
Roscoe C. Giles ◽  
Masud Mansuripur

2003 ◽  
Vol 777 ◽  
Author(s):  
T. Devolder ◽  
M. Belmeguenai ◽  
C. Chappert ◽  
H. Bernas ◽  
Y. Suzuki

AbstractGlobal Helium ion irradiation can tune the magnetic properties of thin films, notably their magneto-crystalline anisotropy. Helium ion irradiation through nanofabricated masks can been used to produce sub-micron planar magnetic nanostructures of various types. Among these, perpendicularly magnetized dots in a matrix of weaker magnetic anisotropy are of special interest because their quasi-static magnetization reversal is nucleation-free and proceeds by a very specific domain wall injection from the magnetically “soft” matrix, which acts as a domain wall reservoir for the “hard” dot. This guarantees a remarkably weak coercivity dispersion. This new type of irradiation-fabricated magnetic device can also be designed to achieve high magnetic switching speeds, typically below 100 ps at a moderate applied field cost. The speed is obtained through the use of a very high effective magnetic field, and high resulting precession frequencies. During magnetization reversal, the effective field incorporates a significant exchange field, storing energy in the form of a domain wall surrounding a high magnetic anisotropy nanostructure's region of interest. The exchange field accelerates the reversal and lowers the cost in reversal field. Promising applications to magnetic storage are anticipated.


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