Transmission and reflection are two fundamental properties of the electromagnetic wave propagation through obstacles. Full control of both the magnitude and phase of the transmission and reflection independently are important issue for free manipulation of electromagnetic wave propagation. Here we employed the equivalent principle, one fundamental theorem of electromagnetics, to analyze the required surface electric and magnetic impedances of a passive metasurface to produce either arbitrary transmission magnitude and phase or arbitrary reflection magnitude and phase. Based on the analysis, a tunable metasurface is proposed. It is shown that the transmission phase can be tuned by 360° with the unity transmissivity or the transmissivity can be tuned from 0 to 1 while the transmission phase is kept around 0°. The reflection magnitude and phase can also been tuned similarly with the proposed metasurface. The proposed design may have many potential applications, such as the dynamic EM beam forming and scanning.

A series of Fe 3 O 4 particle chains with an average particle diameter of 150 nm and different lengths were synthesized by using the self-assembly method at reduced temperature in different synthesizing magnetic fields. The influence of synthesizing magnetic field on the properties of the magnetite particle chains was studied by structural analyses, magnetometry measurement, and ferromagnetic resonance. A uniaxial magnetic anisotropy in the saturation field (H s ), hysteresis loop, and ferromagnetic resonance were observed to increase with increasing synthesizing field. The saturation magnetization and g-factor were found to increase slightly with increasing synthesizing field. The demagnetizing fields and demagnetizing factors were determined from the experimental data of magnetometry measurement, ferromagnetic resonance, and also numerical calculation, which agreed reasonably well. It was found that the magnetization non-uniformity in the chains and the magnetostatic interaction among the chains have an important effect on the shape anisotropy of the chain assembly.

Mesoporous semimetal bismuth film and magnetic metal nickel and cobalt thin films have been electrodeposited from hexagonal or lamellar structured lyotropic liquid crystalline phases with polyoxyethylene surfactant. The liquid crystalline templates are characterized by low-angle X-ray diffraction (XRD) and polarized-light optical microscopy (POM). The metal films are characterized by low-angle and wide-angle XRD, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The magnetic measurements on the mesoporous nickel and cobalt films are shown to have higher coercivity (Hc) than the nonporous polycrystalline films.