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381.
Ferromagnetic nanocomposite (Fe44Co56)77Hf12N11 films were deposited to investigate their intrinsic damping mechanisms due to scattering of itinerant electrons, which carry the magnetic moment of the ferromagnetic transition elements. The films were produced by reactive r.f. magnetron sputtering using a 6 in. Fe37Co46Hf17 target. They were annealed at 400 °C in a static magnetic field, in order to induce in-plane uniaxial anisotropy. Subsequently, the films can be considered as uniformly magnetised. A ferromagnetic resonance frequency (FMR) of around 2.3 GHz could be attained, which was determined by measuring the real and imaginary parts of the frequency dependent permeability up to 5 GHz. The imaginary part, which represents a typical resonance curve, was utilised to obtain its full-width at half-maximum Δfeff (FWHM) for the total damping behaviour characterisation. Thereby, it is possible to extract the intrinsic Gilbert damping parameter αint, which in turn can be decomposed into two additional damping terms αsf and αos allocated to “spin-flip” and “ordinary scattering”, respectively. This result is correlated and discussed in terms of a verified theoretic model, to identify whether damping due to spin-flip scattering and/or ordinary scattering is dominant. 相似文献
382.
Junchao Lu Li Pi Shun Tan Yuheng Zhang 《Physica C: Superconductivity and its Applications》2010,470(21):1920-1927
In this paper, the substitution effect of Sr for La in three non-superconducting system La2−xSrxCu0.94M0.06O4 (M = Fe, Co and Ni) have been systematically studied. As the concentration of Sr increases to around 0.20, the superconductivity is recovered. The peak at 695 cm−1 in the infrared spectra which is assigned to the stretching mode of oxygen atoms in plane induced by M3+ doping is suppressed by Sr increasing, demonstrating that the holes introduced by the Sr substitution have been injected into the CuO2 plane and compensate the localized electrons. These results suggest that the superconductivity recurrence is caused by the carrier compensation. The main origin of superconductivity suppression by the magnetic ions Fe/Co/Ni is the carrier localization effect. 相似文献
383.
王东 《原子与分子物理学报》2018,35(6)
采用能量极小原理研究了Permalloy(Py)/Cu/Co/NiO多层膜结构中层间耦合强度和应力各向异性场对薄膜共振频率的影响,得到共振频率随外磁场强度变化关系式.结果发现外应力场强度和方向对系统共振频率的影响在本文中要强于层间耦合强度和交换各向异性场.外应力场方向对光学模共振频率的影响强于声学模,而外应力场强度对声学模共振频率的影响强于光学模. 相似文献
384.
《印度化学会志》2023,100(2):100915
Recent developments in technology as well as rapid increase in world's population are the major factors that compelled the researchers to pay their attention in seeking some innovative and efficient sources of acquiring energy rather than fossil fuels. There are two basic reasons for which it got popularity firstly day by day declination of fossil fuels secondly their major harmful effects so researchers are struggling for such an alternate that can overcome these two basic problems so solar energy is proven a best solution of these issues because it is found abundantly in nature also it is environment friendly, so research community paid full attention toward it. Another solution of above faced problem is by usage of thermally more efficient fluid that is nanofluid; it is environmental friendly and energy saving too. The nonlinear partial differential equations are reduced to dimensionless form by using some suitable similarity transformations. The approximate solution was attained by MATLAB software using a pure numeric technique known as bvpc4. The effects of the salient parameters on velocity distribution, temperature of Williamson ferro fluid and concentration are physically interpreted and displayed pictorially. Temperature of Williamson ferro fluid intensifies for larger values of thermophoretic and Brownian motion parameters. Boungiorno relation has contrary behavior for concentration field Heat transfer rate dwindles against both Nt and Nb . 相似文献