A ferromagnetic monolayer with competing long-range dipolar interaction, short-range interaction and magnetic uniaxial anisotropy is studied using Monte Carlo simulation. Striped domain patterns are found and reveal the microstructure of the magnetization transition at the ground state via the competing between dipolar interaction and uniaxial anisotropy. We present the finite temperature phase diagram and find a temperature-induced magnetization reorientation from out-of-plane to in-plane phase. The influence of the various interactions on the structure of the striped phase and reorientation behavior has been discussed.

Bi1-xLaxFeO3(x=0, 0.3) thin films were deposited on glass/ITO substrates through Sol-Gel Dip-Coating method and rapid annealing process. The structures were detected by X-ray diffraction patterns, Raman spectrometer and scanning electron microscopy. The magnetic, ferroelectric and optical properties of the films were studied by vibrating sample magnetometer, ferroelectric integrate tester and photovoltaic performance testing system, respectively. The experimental results indicate that BiFeO3 thin film presents rhombohedral perovskite structure and Bi0.7La0.3FeO3 films showed distorted perovskite structure, which were confirmed by XRD patterns and Raman spectrometer. The magnetism and ferroelectric properties of the films were obviously enhanced by La doping. Furthermore, the photocurrent response and photovltaic effect in BLFO thin films were detected.

Based on the Monte-Carlo simulation and fast Fourier transformation-micro-magnetism (FFTM) method, magnetic properties with different parameters for the 4×4 Magnetic Quantum Dot Arrays (QDA) were studied. The calculating processes show that the same calculated results can be obtained by both methods above. But the FFTM method can save much time in obtaining results, which suggest that the method be employed to study more complex systems. The calculated results indicate that there exists obvious difference in the magnetic hysteresis loops with different temperatures, which can be well explained by considering the relationship between the easy-magnetization axis and the organization anisotropy of the QDA system. Furthermore, saturation field (Hs) increases with the dipolar interaction increasing, which is attributed to the competition between dipolar energy (ED) and Zeeman energy (EZ). The calculated results can fit the experimental results very well. Besides, it is found that the dipolar interaction constant D has a great influence on magnetic properties.

In this paper, Fe nanoring model of different degree of eccentricity has been made. Based on the FFTM method and MC simulation method, the magnetic properties of the Fe nanoring, such as hysteresis loops, spin configuration, have been studied. The simulated results indicate that there are typical hysteresis loops and spin-configurations, such as onion-type state and vortex-type state in the system of symmetric Fe nanoring. The hysteresis loops of the eccentric Fe nanoring are similar to symmetric system when the degree of eccentricity is small, but as the degree of eccentricity increased, the magnetization behavior become different. Remanence is almost linearly related to the degree of eccentricity in the system of eccentric Fe nanoring, which can be explained by analyzing the change of spin-configurations in the eccentric Fe nanoring.

As a promising absorber layer, semiconducting Cu2ZnSnS4 (CZTS) can be applied to replace the organic dye in dye-sensitized solar cell for photovoltaic application because of its good stability, suitable band gap energy (~1.5eV) and large absorption coefficient (~104 cm-1). In this paper, successive ionic layer adsorption and reaction (SILAR) method was utilized to deposit CZTS nanoparticles on mesoporous titanium dioxide (TiO2). This solar cell with carbon film coated FTO glass slide as the back electrode showed an open circuit voltage of 380 mV. Preliminary results obtained for solar cells fabricated with this material are promising.