Un-hydrogenated Diamond-like Carbon （DLC） films were prepared by pulsed laser deposition technique at different substrate temperature. The Raman spectra, the absorption and the photoluminescence spectra were measure...Un-hydrogenated Diamond-like Carbon （DLC） films were prepared by pulsed laser deposition technique at different substrate temperature. The Raman spectra, the absorption and the photoluminescence spectra were measured. The dependence of structure and phetoluminescence properties on deposition temperature were studied in detail. The experimental results indicate that the sp^2 sites form small clus ters that consist of both olefinic chains and aromatic ring groups within the sp^3 matrix. With raising deposition temperature,the optical band gaps increase from 1.87 to 2.85 eV. The main band of photoluminescence centered at around 700nm shifts to short wavelength, and the intensity of this band increases. The photoluminescence can be attributed to carrier localization within an increasing sp^2 clusters. It was clarified that the DLC films are ordered with increasing deposition temperature.展开更多
In this work, epitaxial growth of LaMnO3 thin films on different substrates using pulsed laser deposition under tensile and compressive strain was studied. The intrinsic exchange bias effect was observed in the single...In this work, epitaxial growth of LaMnO3 thin films on different substrates using pulsed laser deposition under tensile and compressive strain was studied. The intrinsic exchange bias effect was observed in the single A-type antiferromagnetic LaMnO3 films no matter whether the tensile or compressive strain was supplied by the substrates. Due to the lattice mismatch between the film and different substrates, the intense strain can induce MnO6 octahedral rotation in the bottom region of the film neighboring the substrate, which leads to the distortion of MnO6 octahedron and the net magnetic behavior. However, the upper part maintains the original A-type antiferromagnetic order due to strain relaxation. The exchange bias effect in single films is attributed to the coupling between the bottom canted magnetic part and the upper antiferromagnetic region. The observation of exchange bias in single films on different substrates enables the emergence of a new class of biasing components in spintronics, which are based on strain-engineering.展开更多
文摘Un-hydrogenated Diamond-like Carbon （DLC） films were prepared by pulsed laser deposition technique at different substrate temperature. The Raman spectra, the absorption and the photoluminescence spectra were measured. The dependence of structure and phetoluminescence properties on deposition temperature were studied in detail. The experimental results indicate that the sp^2 sites form small clus ters that consist of both olefinic chains and aromatic ring groups within the sp^3 matrix. With raising deposition temperature,the optical band gaps increase from 1.87 to 2.85 eV. The main band of photoluminescence centered at around 700nm shifts to short wavelength, and the intensity of this band increases. The photoluminescence can be attributed to carrier localization within an increasing sp^2 clusters. It was clarified that the DLC films are ordered with increasing deposition temperature.
基金financially supported by the National Key R&D Program of China (2017YFB0405703)the National Natural Science Foundation of China (51871137, 61434002 and 51571136)the Special Funds of Sanjin Scholars Program
文摘In this work, epitaxial growth of LaMnO3 thin films on different substrates using pulsed laser deposition under tensile and compressive strain was studied. The intrinsic exchange bias effect was observed in the single A-type antiferromagnetic LaMnO3 films no matter whether the tensile or compressive strain was supplied by the substrates. Due to the lattice mismatch between the film and different substrates, the intense strain can induce MnO6 octahedral rotation in the bottom region of the film neighboring the substrate, which leads to the distortion of MnO6 octahedron and the net magnetic behavior. However, the upper part maintains the original A-type antiferromagnetic order due to strain relaxation. The exchange bias effect in single films is attributed to the coupling between the bottom canted magnetic part and the upper antiferromagnetic region. The observation of exchange bias in single films on different substrates enables the emergence of a new class of biasing components in spintronics, which are based on strain-engineering.
