Insitu Plane—View and Cross—Scctional Transmission Electron Microscopy of Fractal Formation in Au／a—Ge Bilayer Films

Fractal crystallization in Au/a-Ge bilayer films has been studied by in situ plane-view and cross-sectional transmission electron microscopy.The experimental evidence suggests that the fractal crystallizaqtion is controlled by both diffusion and reaction processes.The growth kinetics analysis indicates that both diffusion-limited aggregation and random successive nucleation mechanisms play an important role in fractal crystallization in Au/a-Ge bilayer films.     

Nonlinear Shift of the Raman A1 Mode in Ga-Incorporated CuInSe2 Thin Films

Composition dependence of quaternary CuIn1-x GaxSe2 films on Ga content has been systematically investigated by Raman scattering. The dominant A1 mode shifts from 174cm^-1 for CuInSe2 to 185cm^-1 for CuGaSe2 in an approximately polynomial curve other than a linear curve, indicating existence of asymmetric distribution of Ga and In on a microscopic scale in films. With Ga content x 〉 0.3, the significantly broadening and intensity decrease of A1 modes suggest the degradation of crystalline quality of chalcopyrite phase. Additionally, the quenching of additional Raman band at 183cm^-1 for the Ga-rich films reveals that CuAu-ordered phase can coexist in nominal chalcopyrite CuInSe2 films but not in CuGaSe2, due to Ga inhibition effect.     

Insensitivity of Speckle Multiplexing to Multi—longitudinal Modes of Laser in Volume Holographic Storage

If a diode pumped solid state laser is used in a holographic storage system,its multi longitudinal modes may damage the angular selectivity of the hologram amd introduce more cross talk in the system.By theoretical analysis,we found that with adopting the speckle multiplexing scheme,holographic systems are no longer sensitive to the multi longitudinal modes of the laser source,and consequently the damage described above could be well suppressed.Moreover,the following high density storage experimental results also express strong advocacy of this conclusion.this result may greatly prompt the miniaturization of holographic stroage system.     

Apparatus for Real—Time Measurement of Stress in Thin Films at Elevated Temperatures

As a prerequisite of biaxial zero creep experiments, a novel sensitive apparatus is developed for real-time filmstress measurement during thermal cycles. The optical sensor with a fixed multi-beam emitter and a CCD detector is investigated during an annealing process of Ag/Co multilayer thin film. The monitoring plots of stress as functions of temperature and time demonstrate the capability of this set-up. The typical sensitivity for measuring the wafer curvature radius is 2 km.     

Dielectric Enhancement and Maxwell—Wagner Effect in Polycrystalline BaTiO3／Ba0.2Sr0.8TiO3 Multilayered Thin Films

Polycrystalline BaTiO3/Ba0.2Sr0.8TiO3 multilayer thin films were fabricated by pulsed laser deposition onto Pt/Ti/SiO2/Si substrates with various stacking periodicities.The dielectric constant of the films was obviously enhanced with the decrease of the individual layer thickness,while the dielectric loss was kept at a low level comparable to that of the pure Ba0.6Sr0.4TiO3 thin films.The Maxwell-Wagner model is used to explain the experimental data.     

Preparation of Multi—Atom Entangled States with a Single Cavity in a Thermal State

A scheme is suggested for the generation of multi-atom maximally entangled states with a cavity in a thermal state,In this scheme several appropriately prepared two-level atoms are simultaneously sent through the nonresonant cavity.We divide the whole atom-cavity interaction time into two equal parts.At the end of the first part a π pulse is applied to the atome using a classical field.Then the photon-number-dependent shifts on the atomic states are cancelled and the atomic system finally evoloves to a maximally entangled state.     

Projected Shell Model Analysis of Multi—Quasiparticle High—K Isomers in ^174Hf

Multi-quasiparticle high-K states in ^174Hf are studied in the framework of the projected shell model.The calculation reproduces well the observed ground-state band as well as most of the two-and four-quasiparticle rotational bands.Some as yet unobserved high-K isomeric states in ^174Hf are predicted.Possible reasons for the existing discrepancies between calculation and experiment are discussed.It is suggested that the projected shell model may be a useful method for studying multi-quasiparticle high-K isomers and the K-mixing phenomenon in heavy deformed nuclei.     

Preparation of Diamond—Like carbon Films in methane by Electron Cyclotron Resonance Microwave Plasma Source Ion Implantation

Diamond-like carbon(DLC)films were prepared on Si(100) substrates by ion implantation from an electron cyclotron resonance microwave plasma source.During the implantation,650W microwave power was used to produce discharge plasma with methane as working gas,and-20KV voltage pulses were applied to the substrate holder to accelerate ions in the plasma.Confocal Raman spectra confirmed the DLC characteristics of the films.Fourier-transform infrared characterization indicates that the DLC films were composed of sp^3 and sp^2 carbonbonded hydrogen.The hardness of the films was evaluated with a Nano Indenter-XP System.The result shows that the highest hardness valus was 14.6 GPa.The surface rms roughness of the films was as low as 0.104nm measured with an atomic force microscope.The friction coeffcient of the films was checked using a ball-on-disk microtribometer.The average friction coefficient is approximately 0.122.