A Simulation of Rotational Hysteresis Energy Loss in Longitudinal Thin-Film Media

1998 ◽  
Vol 517 ◽  
Author(s):  
Wei Yang ◽  
David N. Lambeth
Keyword(s):  
Thin Film ◽  
Energy Loss ◽  
Hysteresis Loop ◽  
Field Dependence ◽  
Easy Axis ◽  
Anisotropy Field ◽  
Exchange Interactions ◽  
The Other ◽  
Rotational Hysteresis ◽  
Hysteresis Energy Loss

AbstractThe field dependence of the rotational hysteresis energy loss was simulated for longitudinal thin-film media with the purpose of examining the validity of this method for measuring the anisotropy field. The field at which the rotational hysteresis vanishes, which is usually taken as the experimentally measured anisotropy field, was found to be smaller than the real anisotropy field when intergranular magnetostatic and exchange interactions are included in the simulations. Hence the rotational hysteresis method may result in an underestimation of the anisotropy field for the films with non-negligible grain interactions. To confirm this experimentally, two CoCrTa films, one with strong in-plane easy axis texture and the other with uniaxially aligned grain easy axes, were prepared under the same conditions. The anisotropy field determined by the rotational hysteresis of the first sample was found to be smaller than the more accurate value obtained from the hard axis hysteresis loop of the second sample.

Successive Magnetic Transitions on Single Crystal Cu3(OH)4SO4

2011 ◽  
Vol 170 ◽  
pp. 194-197
Author(s):  
Shigeo Hara ◽  
Hirohiko Sato
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Single Crystals ◽  
Field Dependence ◽  
Easy Axis ◽  
The Other ◽  
Magnetic Transitions ◽  
Copper Hydroxide ◽  
High Quality ◽  
Measured Field

Cu3(OH)4SO4, a parallel Cu (S = 1/2) triple chain system, is an interesting magnet because an idle-spin state is expected on the central chain. We have succeeded in growing high-quality single crystals of Cu3SO4(OH)4 by a hydrothermal method from copper sulfate and copper hydroxide. We measured field dependence of the magnetization on a single crystal under various directions of magnetic field up to 7 T. We found a clear magnetic anisotropy and confirmed that the existence of the easy axis lies in the ac plane. Under magnetic fields parallel to the c-axis and the a-axis at 2.5 K, we observed field-induced successive magnetic transitions. In the case of B//c, two anomalies of the magnetization are observed at 0.9 and 1.7 T, On the other hand, there are broad anomalies in the magnetization at 3.7 and 5.6 T in the case of B//a.

Relation of Field Dependence to the “Philosophies of Human Nature”

1969 ◽  
Vol 24 (1) ◽  
pp. 197-198
Author(s):  
Robert B. Duke
Keyword(s):  
Human Nature ◽  
Field Dependence ◽  
The Other ◽  
Field Independence ◽  
Personality Variables ◽  
Positive View ◽  
Embedded Figures Test ◽  
Embedded Figures ◽  
Positive Correlations ◽  
The One

To study the function of personality variables in the perception of other people, 52 undergraduate males were administered the Philosophies of Human Nature Scale and the Embedded-figures Test. Relatively low but significant positive correlations were found between field independence and trustworthiness, altruism, and the positive view of human nature. There was no significant correlation between field independence and strength of will, independence, complexity, and variability. Apparently, the personality of the one perceiving is relevant to what is perceived in the other person.

Study on preparing PLT(28) thin film and its electro-optic effect

1998 ◽  
Vol 13 (5) ◽  
pp. 1266-1270 ◽  
Author(s):  
Ai-Li Ding ◽  
Wei-Gen Luo ◽  
P. S. Qiu ◽  
J. W. Feng ◽  
R. T. Zhang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Faraday Effect ◽  
The Other ◽  
Ceramic Powders ◽  
Glass Substrates ◽  
Annealing Conditions ◽  
Electro Optic

PLT(28) thin films deposited on glass substrates were studied by two sputtering processes. One is an in situ magnetron sputtering and the other is a low-temperature magnetron sputtering. The sintered PLT ceramic powders are used as a sputtering target for both processes. The influences of sputtering and annealing conditions on structure and crystallinity of the films were investigated. The electro-optic (E-O) properties of PLT(28) thin films prepared by the two processes were determined by a technique according to Faraday effect. The researches showed the E-O properties were strongly affected by the sputtering process. The film with larger grains exhibits stronger E-O effect. The quadratic E-O coefficient of PLT(28) thin film varies in the range of 0.1 × 10−16 to 1.0 × 10−16 (m/v)2.

scholarly journals Dynamics of Magnetization in Multilayer TbCo / FeCo Structures under the Influence of Femtosecond Optical Excitation

2019 ◽  
Vol 7 (3) ◽  
pp. 50-58 ◽  
Author(s):  
N. A. Ilyin ◽  
A. A. Klimov ◽  
N. Tiercelin ◽  
P. Pernod ◽  
E. D. Mishina ◽  
...  
Keyword(s):  
Easy Axis ◽  
Uniaxial Anisotropy ◽  
Anisotropy Field ◽  
Optical Excitation ◽  
Spin Precession ◽  
Heat Diffusion ◽  
Easy Magnetization ◽  
Test Beam ◽  
Magnetic Subsystem ◽  
Hard Axis

The need to study ultrafast processes in magnetism is due to the prospects for creating ultrafast magnetic recording and ultrafast spintronic devices. In order to excite the magnetic subsystem femtosecond optical pulses are used. The excitement is manifested as in spin precession. In metals, the material is heated first due to significant optical absorption, and significant Joule losses occur. The most important task is to search for materials in which spin processes are excited without heating. Obvious candidates are weakly absorbing materials, such as ferrite garnets. However, the range of such materials and the range of their functionality are limited.The purpose of this work is to study the dynamics of systems with nonthermal mechanisms of spin precession excitation. Such excitation is possible in ferromagnetic / antiferromagnetic heterostructures with exchange interaction, provided that the recombination time of photocarriers is shorter than the time of heat diffusion. Multilayer TbCo / FeCo structures of the near IR range were investigated for a femtosecond optical pulse. The spin dynamics are compared with the direction of the wave vector of the exciting pulse along and perpendicular to the axis of easy magnetization of the structures (“easy axis” and “hard axis” geometry, respectively). It is shown that in case of “easy axis” geometry the determinative mechanism is the thermal interaction. When the system is exposed to an excitation pulse, this mechanism leads to a decrease in the projection of magnetization on the direction of propagation of the test beam. In case of “hard axis” geometry, the magnetization turns to the magnetic field at the initial stage. Then it precesses and relaxes to an equilibrium angular orientation. Such dynamics indicate a rapid recovery of the uniaxial anisotropy field after laser irradiation. The presented results demonstrate an ultrafast change in the magnetic anisotropy induced during the fabrication of the heterostructure under study, which may be of interest for optical control of the orientation of the magnetization.

Field dependence of magnetoresistance in epitaxial single-crystal La2/3Ca1/3MnO3-δ thin film

1999 ◽  
Vol 42 (1) ◽  
pp. 99-105
Author(s):  
Kebin Li ◽  
Rongsheng Cheng ◽  
Shouguo Wang ◽  
Zhixiang Chen ◽  
Jun Fang ◽  
...  
Keyword(s):  
Thin Film ◽  
Single Crystal ◽  
Field Dependence
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