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A simple magnetic modulation structure of the exchange-coupling FePt/FeNi bilayer film is fabricated and studied for its magnetization dynamics using time-resolved magneto-optical polar Kerr spectroscopy. It is found that two spin-wave modes can be excited. One is fixed at ∼3.2 GHz in frequency for any external field and may serve as a frequency-stabilized spin-wave filter, while the other is external field dependent. In contrast, only the external field-dependent mode is excited in single-layer FeNi, supporting the localized origin of the mode at ∼3.2 GHz, which is confined to a thin exchange-coupling region. The other external field-dependent mode in frequency is attributed to the Kittel mode. [ABSTRACT FROM AUTHOR]

An interference phenomenon in femtosecond four-wave mixing and pump-probe experiments on AlGaAs/GaAs multiple-quantum-well films is observed, which is interpreted as the interference of Rayleigh scattering field and the third-order polarization of the sample. Based on the Rayleigh scattering mode, a population relaxation time of 150 fs and a dephasing time of 44 fs of the sample are deduced. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The Sb6Te4/VO2multilayer thin films are prepared by magnetron sputtering and the potential application in phase change memory is investigated in detail. Compared with Sb6Te4, Sb6Te4/VO2multilayer composite thin films have higher phase change temperature and crystallization resistance, indicating better thermal stability and less power consumption. Also, Sb6Te4/VO2has a broader energy band of 1.58 eV and better data retention (125°C for 10 y). The crystallization is suppressed by the multilayer interfaces in Sb6Te4/VO2thin film with a smaller rms surface roughness for Sb6Te4/VO2than monolayer Sb4Te6. The picosecond laser technology is applied to study the phase change speed. A short crystallization time of 5.21 ns is realized for the Sb6Te4(2 nm)/VO2(8 nm) thin film. The Sb6Te4/VO2multilayer thin film is a potential and competitive phase change material for its good thermal stability and fast phase change speed. [ABSTRACT FROM AUTHOR]

After compositing with SiO2 layers, it is shown that superlattice-like Sb/SiO2 thin films have higher crystallization temperature (∼240°C), larger crystallization activation energy (6.22 eV), and better data retention ability (189°C for 10 y). The crystallization of Sb in superlattice-like Sb/SiO2thin films is restrained by the multilayer interfaces. The reversible resistance transition can be achieved by an electric pulse as short as 8 ns for the Sb(3 nm)/SiO2(7 nm)-based phase change memory cell. A lower operation power consumption of 0.09 mW and a good endurance of 3.0 × 106 cycles are achieved. In addition, the superlattice-like Sb(3 nm)/SiO2(7 nm) thin film shows a low thermal conductivity of 0.13 W/(m·K). [ABSTRACT FROM AUTHOR]