Solid State Phenomena Vols. 181-182

Abstract: The influence of deposition temperature (Ts) on glass/stainless steel-based intrinsic amorphous/microcrystalline silicon thin film prepared at different temperature was investigated by PECVD technology. The crystallization ratio and grain size of the silicon thin film at different deposition temperature is studied. The results reveal that the crystallization ratio and grain size of silicon thin film changed along with Ts. The crystallization ratio and grain size of the silicon thin film become larger when Ts=400 °C. On this work, optimal μc-Si:H can be obtained at 400°C deposition temperature in the suitable experimental conditions.

Abstract: Crystal structure and microwave dielectric properties of Ca [(Li_1/3Nb_2/3) _0.95Zr_0.05]O_3−δ−xTiO₂(0≤x≤0.1) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.02~0.1. With an increasing of Ti4+ content, the Qf value decreased due to a decrease of the degree of B-site 1:2 ordering. However, the τf value increased from-14.7ppm /°C to-6.9ppm/°C. When x=0.04, the optimum microwave dielectric properties: εr=31.1, Qf =21640GHz and τf =−8.8 ppm/°C.

Abstract: Undoped amorphous silicon film deposited by PECVD,and annealed by rapid tharmal process,then have been studied by using micro-Raman scattering, X-ray diffraction and scanning electron microscope.It is found that crystallized silicon films is different at different annealing temperatures, there exists a better annealing temperature.

Abstract: Two coupled axially phase matched parametric four-wave mixings have been achieved in Rb vapor by using broad bandwidth laser pulses. Coherent radiations at 420 nm produced by difference-frequency optical wave mixing processes were detected and a pump-probe scheme was employed to record time varying characteristics of the parametric four-wave mixing signals. Quantum beatings at 608 cm^-1 and 70 cm^-1 were retrieved from the time varying signals by Fourier transform. Moreover, time dependent Fourier transform was utilized to analyze the dynamics of quantum beatings. The results indicate that two wave packets associated with the two quantum beating frequency components interact strongly and the quantum beating dynamics can be controlled by adjusting Rb number density.

Abstract: The effect of sodium chloride on the sol-gel synthesized silica colloidal particles has been investigated. The silica colloidal particles in the size range of 420-800 nm were synthesized from the hydrolysis and condensation of tetraethyl orthosilicate by varying the amount of sodium chloride from 15 to 30 mg while keeping the tetraethyl orthosilicate (20 ml), ethanol (125 ml), ammonia (6 ml) and distilled water (18 ml) fixed. Scanning electron microscopy (SEM) was employed to analyze the morphology of the synthesized silica particles. Our results demonstrated that: (1) sticky and spongy silica spheroids were resulted if the amount of sodium chloride was less than 15 mg; (2) spherical silica particles were resulted with good monodispersity when the amount of sodium chloride was in the range of 22-24 mg; and (3) silica spheres were obtained but with a wide size distribution when the amount of sodium chloride was more than 26 mg.

Abstract: The N-doped TiO₂ nanotube arrays were prepared by electrochemical anodization and thermal annealing in ammonia flux. All the undoped and N-doped TiO₂ nanotube arrays were pure anatase phase and the N-doped TiO₂ shows obviously enhanced absorption intensity in the visible light region. The investigations on the low-frequency E_g anatase mode of Raman spectra verify that the crystallite size increases from 7.5 nm to 8.5 nm with the increase of the doped nitrogen temperature. The ratio of oxygen atoms to titanium atoms is 2.419 after titania being annealing in NH₃ air stream. It could be concluded that the size effect and oxide vacancies introduced by nitrogen doping lead the great increase of UV-Vis absorption for N-doped TiO₂ nanotubes.

Abstract: By PECVD deposition technology, we mainly investigated the influence of P_RF (radio frequency power) on glass/steel-based intrinsic amorphous/microcrystalline silicon thin film prepared at 300°C. We study the crystallization ratio, grain size of the silicon thin film specially. The results reveal that the crystallization ratio and grain size of the silicon thin film changed along with RF power. The silicon thin film crystallization ratio and grain size changed sharply when P_RF =70 W. On this work we think ideal μc-Si:H can be obtained at P_RF= 70 W and in the suitable experimental conditions.

Abstract: With the development of DPM (digital phase microscopy) and FCM (flow cytometry), techniques of cell recognition are getting more and more applications in many fields. Researches on the information from cells are very important to these techniques. In this paper, focusing on the technique of analyzing light scattering information and its relation with the morphological structures of the leucocytes and erythrocytes have been done. Based on the VirtualLab simulation techniques, the light scattering images of amplitude, phase and polarization of these typical cells have been obtained. It is found that the amplitude, phase and polarization of these cells are closely related to their morphological structures by analyzing the images, which is very useful to identify biological cells.

Abstract: Electrochemical deposition of copper from copper chloride aqueous electrolyte on porous silicon (PS) substrate was investigated in the current density range of 5 mA/cm² to 35 mA/cm². Scanning electron microscopy (SEM) was utilized to characterize the surface morphology of as-electrodeposited PS. SEM images illustrate that the applied current density has a profound influence on the shape of copper crystal electrodeposited on the top surface of PS films. When the applied current density was fixed at 5mA/cm², most of the copper crystals are in the shape of cube along with a small number of cuboid-shape. With the increasing current density, cuboid-shaped copper crystals gradually vanished. When the current density is up to the 35mA/cm², we surprisingly observe that the cube shape predominates simultaneously with the emergence of truncated tetrahedron. A tentative explanation for the growth mechanism of copper crystal having various shapes is explored.

Abstract: Crystal structure and microwave dielectric properties of (Ca_1-xPr_x) [(Li_1/3Nb_2/3)_0.95Zr_0.15]_3+δ (0.0≤x≤0.2, CPLNZ) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.0~0.08. With an increase of Pr³⁺ content, the quality factor value firstly increased, and then began to decrease at x=0.06 due to a decrease of the degree of B-site 1:2 ordering. The variation of τ_f with tolerance factor was discussed. When x=0.06, the optimum microwave dielectric properties: the permittivity is 33.2, the quality factor is 17120 GHz，and the temperature coefficient of resonator frequency is −5.7×10⁻⁶/°C.