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The structural analysis of a three-component Fibonacci (3CF) Ta/Al multilayer after extensive aging at room temperature was conducted. The objectives were to assess the long-term material properties of Ta/Al multilayers as well as the effect of degradation-induced disorder on the quasiperiodic diffraction spectrum. Results indicate that Ta/Al bilayers are unsuitable for multilayer applications due to the lack of thermal stability even at room temperature.

Spin-dependent transport in quasiperiodic cascade junctions of a ferromagnetic metal (FM) and semiconductor (SC), where FM and Sc are arranged in the Fibonacci sequence, is examined. The studies have shown that spin-up and spin-down electrons possess different bandgap structures against the Rashba spin-orbit wave vector.

The spin-dependent transport in ferromagnetic metal (FM)/semiconductor (SC) cascade junctions is examined. The spin polarization of tunneling electrons is reversed by inducing the impurity, such as changing the magnetization of central FM layer, and the spin polarization is enlarged by increasing the cell number in the FM/SC cascade junctions.

The influence of the number and the thickness of the silicon spacer layer on the optical and structural properties of single and multilayers of self-assembled Ge/Si(001) islands is examined. The results have shown the optimal growth sequence that needs to obtain homogeneous and ordered multilayers.

We obtain analytically a universal expression of the resonant energies for any one-dimensional (1D) models with the defects having symmetric internal structures. In a 1D periodic system with the on-site energy ε0 = 0 and a nearest-neighbor matrix element t0 = 1.0, two classes of the most interesting and simplest wavefunction behaviors are numerically obtained for the resonant energies around (a) 0, ±1, (b) ±(√5-1)/2, √2, ±√3, respectively. We show that similar wavefunction behaviors can be found widely in many quasiperiodic and random systems where the delocalization phenomena are predicted. We suggest that the envelope of these wavefunctions can be generally used as a criterion of delocalization of electronic states in 1D random and quasiperiodic lattices. [ABSTRACT FROM AUTHOR]

Multiple perfect transmissions of electromagnetic waves are found in the photonic band gap of the symmetric dielectric heterostructures (SDH) constructed as (AB)nBm(BA)n, where A and B stand for different dielectric materials, and m and n are the repeating numbers of the units. The photonic frequency and the mode number of resonant transmissions therein can be manipulated by varying m, and the quality factor Q of the perfect transmission peak increases exponentially with increasing n. These features are experimentally demonstrated in a SDH of TiO2/SiO2 for visible and near infrared light. The possible applications of SDH for the wavelength division multiplexing system are discussed. [ABSTRACT FROM AUTHOR]

Examines the fabrication of quasiperiodic tantalum/aluminum multilayer films by magnetron sputtering. Structure characterization of the multilayered films; Use of x-ray diffraction technique; Application of Fibonacci films as optical elements.