CoPt/C NANOGRANULAR MAGNETIC THIN FILM

Abstract

Granular Co 30 Pt 70/ C and Co 45 Pt 55/ C films, consisting of nanoparticle CoPt phases embedded in a carbon matrix, have been made by co-sputtering from CoPt and C targets using a tandem deposition mode. X-ray diffraction shows the existence of hard CoPt phase embedded in an amorphous C matrix after annealing. The coercivities for CoPt/C are strongly dependent on C and Pt composition. Films with coercivity of up to 5.4 kOe and grain size of 7 nm can be obtained. The development of shoulder in hysteresis loop may be contributed to the co-existence of magnetic soft CoPt 3 and hard CoPt phases and the magnetic interactions between them. High remanence Mr/Ms (>0.8) found in our samples indicates the presence of the intergranular interactions in the samples. Observed positive contributions of δm also give evidence of the existence of exchange interaction. High coercivity and large Mr/Ms make granular CoPt/C film with magnetic nanoparticles very attractive for next-generation high-density recording.

Abundant solutions of Wick-type stochastic fractional 2D KdV equations

“…Hence, we set the solution of Eq. ( 11) by: (13) where Φ(ξ ) satisfies the fractional Riccati equation (8). By substituting Eq.…”

“…Obviously, there are an infinite number of particular solutions for the system Eqs. ( 14)- (19) together with the fractional Riccati equation (8) resulting in many different cases. The properties of generalized exponential, hyperbolic and trigonometric functions yield that there exists a bounded open set D ⊂ R 2 × R + , q < ∞, r > 0 such that the solution u(x, y,t, z) of Eq.…”

“…There are many methods for calculating the approximate solutions for nonlinear fractional partial differential equations, such as the variational iterations method, [3] Adomian decomposition method, [4,5] the homotopy perturbation method, [6,7] and the expansion-function method. [8][9][10][11][12] The exact solutions for nonlinear fractional partial differential equations are still under study. Li and He [13] introduced complex transformation for reducing fractional differential equations into ordinary differential equations, so that all analytical methods for advanced calculus can be easily applied to fractional calculus.…”

Solitary and Periodic Waves in Coupled KdV Equations with Different Linear Dispersion Relations

“…[15], the Painlevé analysis, having been successfully used to obtain five types of Painlevé-integrable coupled KdV equations related to system (4) with α 3 = γ 3 = 1 [10] and two Painlevé-integrable coupled KdV models with different linear dispersion relations. [16−17] The tanh method, [18] the F-expansion method, [19] the homogeneous balance method, [20] the Lie symmetry method, [21−22] Darboux transformation, [23−24] et al are all the widely used techniques for seeking analytical solutions for these coupled KdV systems.…”