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The bending problem of a magnetic film-nonmagnetic substrate cantilever system is studied by using the principle of energy
minimization. Emphasis is placed on the analysis of geometrical and physical parameter dependence of the neutral plane, internal
film stress and strain of the cantilever system, and then the influence of such a parameter on the bending characteristic
is presented. The results indicate, owing to the anisotropic expanding feature of the magnetostriction, that the neutral plane
is generally anisotropic, and moves downwards rapidly with the increasing thickness ratio. Meanwhile, the bounding rigidity
of substrate on the film will decrease with the increasing thickness ratio, and thus release the film stress, i.e., it decreases,
but the film strain increases. The effect of Poisson’s ratio of the materials on the film strain, the stress and the neutral
plane in the direction transverse to the magnetization is prominent. For the strain and the stress in the magnetization, however,
the role of Poisson’s ratio is inconspicuous. This property is due to the initiative elongating (or contracting) feature of
the magnetic film along its magnetization.
Supported by the National Natural Science Foundation of China (Grant No. 10762001), the Key Project of the Chinese Ministry
of Education (Grant No. 206024), and the Program for New Century Excellent Talents in University of China (Grant No. NCET-2005-0272) 相似文献
2.
Using the principle of minimal energy and S-W model, the exchange bias for ferromagnetic/antiferromagnetic bilayers has been
investigated when the uniaxial anisotropy is misaligned with the exchange anisotropy. According to the relation between the
energy of the bilayer and the orientation of ferromagnetic magnetization, it is found that the bilayer will be in the monostable
state or bistable state when the external field is absent in the initial magnetization state. The monostable state or bistable
state of the bilayer, which determines the angular dependence of exchange bias directly, is controlled by the competition
between the exchange anisotropy and uniaxial anisotropy. When the applied field is parallel to the intrinsic easy axes and
intrinsic hard axes, one of the switching fields of the hysteresis loop shows an abrupt change, while the other keep continuous
by analyzing the magnetization reversal processes. Consequently, the exchange bias field and the coercivity will show a jump
phenomenon. The numerical calculations indicate that both the magnitude and direction of the exchange anisotropy will significantly
affect the angular dependence of exchange bias. The jump phenomenon of exchange bias is an intrinsic property of the bilayer,
which is dependent on the interfacial exchange-coupling constant, the orientation of the exchange anisotropy, the thickness
and uniaxial anisotropy constant of the ferromagnetic layer. 相似文献
3.
Yang XiaoDong Li Jie Mao LiJun Li GuoHong Ma XiaoMing Yan TaiLai Mao RuiShi Yang JianCheng Yuan YouJin Parkhomchuk Vasily Reva Vladimir 《中国科学:物理学 力学 天文学(英文版)》2011,54(2):274-278
The six species heavy ion beam was accumulated with the help of electron cooling in the main ring of Cooler Storage Ring of Heavy Ion Research Facility in Lanzhou (HIRFL-CSR). The ion beam accumulation dependence on the parameters of cooler was investigated experimentally. The 400 MeV/u 12C6+ and 200 MeV/u 129Xe54+ were stored and cooled in the experimental ring CSRe, and the cooling force was measured in different conditions.
相似文献4.
GuoHong Chen Xin Wang XiaoQian Jin LingYan Liu WeiXing Chang Jing Li 《中国科学:化学(英文版)》2010,53(6):1294-1301
This paper presents a versatile reagent for epoxide cleavage. The allyltin tribromide could act as a novel and easily prepared allylation reagent and halide atom donor to convert epoxides to the corresponding homoallyl alcohols and halohydrins in high yields with excellent regioselectivities under mild reaction conditions, respectively. It could also act as a Lewis acid to catalyze the ring opening reactions of epoxides with alcohols. 相似文献
5.
Xuedong Li Hongli GuoHong Liu Dingquan XiaoJianguo Zhu 《Applied Surface Science》2011,257(15):6756-6760
0.95Pb(Sc0.5Ta0.5)O3-0.05PbTiO3 thin films were prepared on LaNiO3/SiO2/Si substrate by radio frequency magnetron sputtering, and the films were annealed subsequently with repeated many times by two approaches: normal one-step rapid thermal annealing and innovative two-steps rapid thermal annealing. X-ray diffraction demonstrates that all the films were preferred (1 0 0) oriented and an appropriate repeat of annealing process can enhance perovskite phase of the films. Scanning electron microscopy suggests that the films treated by two-steps rapid thermal annealing show crack-free, uniform size grains and dense microstructure. Measurement of remnant polarization and leakage current dependence of electric field confirms that the films treated by two-steps rapid thermal annealing exhibit better ferroelectric properties than the films treated by one-steps rapid thermal annealing. The results reveal that microstructure plays an important role in enhanced ferroelectric properties of the 0.95Pb(Sc0.5Ta0.5)O3-0.05PbTiO3 thin films. 相似文献
6.
We present a new topological invariant to describe the spacetime defect in Riemann- Cartan manifold. By means of the φ-mapping theory and the rank-two topological tensor current (associated to the new topological invariant), we show that there must exist many string objects which naturally generated from the zero points of φ-mapping and is quantized in the topological level under the condition that the Jacobian J(φ/ν) ≠ 0. When J (φ/ν) = 0, we find that there exists a crucial case of branch process. Based on the implicit function theorem and the Taylor expansion, the origin and bifurcation of the strings are detailed in the neighborhoods of the limit points and bifurcation points of φ-mapping, respectively. 相似文献
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