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Effect of Structural Potential on Magnetic Vortex Solitons in Spatially 1D-Extended Josephson Junction

100%

Al-Khawaja S.

Soliton evolution in spatially extended Josephson junction is studied for three types of ad hoc structural potentials describing tunnelling magnetic flux vortices; symmetric, ratchet and double-well. Setting from the inline geometry of the junction, the soliton dynamics could be modelled by the perturbed sine-Gordon equation. Numerical solutions of the latter equation yielded the soliton waves of the fluxon phase, for boundary conditions imposed on the system upon variation of the dispersion parameter α. It has been found that a change in the soliton waveform and intensity occurs as α goes higher, in dependence on the functional of the potential and its symmetry properties. For ratchet and double-well potential at α=0.5, a time-dependent forcing has been found to endorse the balance between dispersion and nonlinearity, jointly with enhancing the stability of the soliton wave. The McLoughlin-Scott perturbation theory has been adopted to show that the system conserves energy due to the delicate balance between nonlinearity and dispersion, so that the soliton keeps robust as it temporally evolves.

Optical and Electrical Characterization of (002)-Preferentially Oriented n-ZnO/p-Si Heterostructure

63%

Abdallah B., Al-Khawaja S.

Acta Physica Polonica A

2015

vol. 128

issue 3

283-288

In this paper, preferentially oriented (002) ZnO thin films have been grown on Si (100) and glass substrates using radio frequency magnetron sputtering. The dependence of the quality of the ZnO thin films at different substrate temperatures on the growth is studied. A ZnO thin film with c-axis-oriented würtzite structure is obtained at a growth temperature from 200 to 400°C. X-ray diffraction shows that the full width at half maximum θ -2θ of (002) ZnO/Si is located at approximately 34.42°, which is used to infer the grain size that is found to be 17 nm to 19.7 nm. The FWHM is 9.5° to 8° in rocking curve mode, from which the crystalline quality has been determined. The texture degree demonstrates the improvement in quality with the increase of substrate temperature, which is best at 400°C. The band gap extracted by UV transmittance spectrum has been identified as 3.2 eV at 400°C. The electrical characteristics via C-V and I-V measurements on the basis of the heterojunction thermal emission model confirm the domination of high-density grain boundary layer existing at the interface. The transport currents indicate to the presence of space-charge-limited current and trap-charge-limited current mechanisms.

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2 Acta Physica Polonica A

1 2015

1 2013

2 Al-Khawaja S.

1 Abdallah B.

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Effect of Structural Potential on Magnetic Vortex Solitons in Spatially 1D-Extended Josephson Junction

Optical and Electrical Characterization of (002)-Preferentially Oriented n-ZnO/p-Si Heterostructure