Sun Hui-yuan

Optical and magnetic properties of porous anodic alumina films embedded with Co nanowires

A simple method to tune the optical properties of porous anodic alumina (PAA) films embedded with Co nanowires (PAA@Co nanocomposite films) is reported in this paper. The films exhibit vivid structural colors and magnetic properties. The optical properties of the films can be effectively tuned by adjusting the thickness of the PAA template. The deposition of Co nanowires greatly increases the color saturation of the PAA films. The theoretical results of the changes in structural color according to the Bragg—Snell formula are consistent with the experimental results. PAA@Co films can be used in many areas, including decoration, display, and multifunctional anti-counterfeiting applications.

Influence of in-plane field on the stability of vertical Bloch line chains in hard domains of Garnet bubble films

The stability of vertical Bloch line (VBL) chains was statistically studied for all three types of hard domains in garnet bubble films subjected to an in-plane field Hip. With a set of integrate data taken from seven bubble samples and with two typical figures of a sample, four main features of the behavior of VBL chains subjected to Hip were summarized.

Synthesis and Characteristics of Electrodeposited CoxZn1?x Nanorods

CoxZn1−x nanorod arrays were fabricated by electrodeposition in porous anodic aluminum oxide templates at different electric potentials. X-ray diffraction and transmission electron microscopy indicate that highly-ordered and uniform nanorods have been fabricated. The amounts of Co and Zn contents are investigated using energy dispersive spectroscopy, which demonstrates that the atom ratio of the alloy nanorods changes with the deposition potential. In addition, magnetic measurements show that the magnetic isotropy Co-rich CoZn nanorods will change to magnetic anisotropy nanorods with the easy axis parallel to the rod long axis with decreasing Co content.

Influence of Temperature on Equilibrium Separation Between Vertical Bloch Lines in OHBs in Garnet Bubble Films

The diameters of the ordinary hard bubbles (OHBs) and soft bubbles in epitaxial garnet films are measured under the microscope at various temperatures. It is found that the bubble diameters of OHBs increase with temperature, and it is concluded that the equilibrium separation between two neighbouring vertical Bloch lines (VBLs) Seq is widened with increasing temperature. At the same time, the results can be understood simply as that there are more VBLs in the domain walls of the first dumbbell domains (IDs) than those in walls of OHBs at the same temperature.

Influence of Heating Rate on Morphologies and Magnetic Properties of α-Fe2O3

A variety of hematite microstructures are synthesized through oxalic acid-assisted thermal treatment of iron films sputtered onto glass substrates. Petal-like α-Fe2O3 nanoslices and honeycomb-like α-Fe2O3 particles of micrometer sizes are obtained after annealing at 500°C but with different rates of heating to the final annealing temperature. Structures and morphologies of the samples are studied by means of x-ray diffraction, scanning electron microscopy and atomic force microscopy. These structures are believed to be formed during the period of increasing temperature to the final annealing temperature. Superconducting-quantum-interference-device magnetometer measurements show room-temperature ferromagnetism in these samples.