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排序方式: 共有811条查询结果,搜索用时 135 毫秒
1.
A. Peláiz-Barranco O. García-Zaldívar F. Calderón-Piñar 《Solid State Communications》2005,133(8):515-519
The Ac behaviour of PLZT 6/80/20 ferroelectric ceramics was analyzed around and above the phase transition. Two relaxation processes are identified, showing that the so-called ‘universal relaxation law’ holds for the ceramics. A critical point in the values of the Ac conductivity, around the temperature corresponding to the maximum of the dielectric losses, is observed below the transition temperature due to the relaxor behaviour. The frequency dependence of the Ac conductivity at various temperatures and the hysteresis loops show classical relaxor behaviour with a diffuse phase transition. 相似文献
2.
J. -Ph. Jay J. Ben Youssef H. Le Gall 《Journal of magnetism and magnetic materials》2002,240(1-3):287-290
The dynamic response of trilayer magnetoresistive permalloy/Cu/Co films was studied by high-frequency permeability spectra measurements. The resonance frequency is shown to depend on the interlayer copper thickness. This dependence is related to exchange coupling between permalloy and cobalt and the interaction field is estimated using the Landau–Lifschitz–Gilbert model. 相似文献
3.
The effect of dynamical exchange interactions on the dielectric function of a two-dimensional electron gas is studied using a variational approach. Exchange effects are introduced via the local-field correction. The variationally obtained local-field factor is compared to the earlier perturbative result to first order in the electron-electron interaction. 相似文献
4.
We explore the magnetic heat capacity in exchange-biased ferromagnet/antiferromagnet bilayers theoretically. We show that changes in the antiferromagnetic structure due to the reversal of the ferromagnet layer can be detected by distinct features in the heat capacity. This offers a method for probing antiferromagnetic domains in exchange-biased systems. 相似文献
5.
主要证明了在不存在交易成本的完全市场条件下连续时间欧式触销式双障碍买权贴现到0时刻的价值过程为鞅,并且给出了对应单障碍买权价值过程的鞅性质.同时还讨论了执行价格为随机的触销式双障碍买权的鞅性质,给出了任意时刻 t(0≤ t≤T)其内在价值的表达式. 相似文献
6.
7.
The electronic structure and magnetism of SmCo7-xZrx alloy are investigated using the spin-polarized MS-X. method. The results show that a few of electrons are transferred to the Sm(5d0) orbital due to orbital hybridization between Sm and Co atoms. The exchange interactions between 3d and 5d electrons are more important than the polarization effects of the conductive electrons, thus it is the main reason resulting in the long-range ferromagnetic order in SmCo7-xZrx. The Curie temperature of SmCo7-xZrx is generally lower than that of corresponding pure Co, which may be explained by the weaker average coupling strength between Co lattices due to some negative couplings mainly occurring of 2e site. The calculated results for the Sm5Co32Zr2 cluster may lead to a better understanding of why SmCo7-xZrx is stable phase. Since the spin-up DOS peak of d electrons at EF arises and the bonding of electrons at EF strengthens with increasing Zr concentration, which results in the internal energy of the system decrease, the stable ferromagnetic order forms in SmCo7-xZrx. 相似文献
8.
K. Kolwas 《Applied physics. B, Lasers and optics》1998,66(4):467-470
Received: 27 August 1997/Revised version: 7 November 1997 相似文献
9.
10.
D. Płusa J. J. Wysłocki B. Wysłocki R. Pfranger 《Applied Physics A: Materials Science & Processing》1986,40(3):167-170
From measurements of the magnetic domain widthsD versus grain thicknessL, we have determined the domain wall energy in the demagnetized state for a sintered Nd15Fe77B8 magnet: = 56 erg/cm2. Using this wall energy and the published magnetocry-stalline constantK
1=4.9×107 erg/cm3, we have calculated the exchange constantA=4.0×10–6 erg/cm, domain wall thickness
B=89 Å, and the critical diameter for single domain particlesD
c=0.67 m. 相似文献