The grain size and surface morphology of sputtered Au films are studied by x-ray diffraction and atomic force microscope. For as-deposited samples the grain growth mechanism is consistent with the two-dimensional （2D...The grain size and surface morphology of sputtered Au films are studied by x-ray diffraction and atomic force microscope. For as-deposited samples the grain growth mechanism is consistent with the two-dimensional （2D） theory, which gives relatively low diffusion coefficient during deposition. Annealing process demonstrates the secondary grain growth mechanism in which the thickness dependence of grain boundary energy plays a key role. The surface roughness increases with the increase of grain size.展开更多
The possibility of cooling a system from liquid helium temperature, 4.2 K, using a tunnel junction refrigerator is analysed. Calculations show that the device can be used over a wide temperature range from 4 K down to...The possibility of cooling a system from liquid helium temperature, 4.2 K, using a tunnel junction refrigerator is analysed. Calculations show that the device can be used over a wide temperature range from 4 K down to well below 1 mK with necessary cooling power. However, several serious difficulties must be overcome before the method can be used in low temperature laboratories.展开更多
The temperature-driven spin reorientation transition of magnetron sputtered Ni/Si （111） systems has been studied. The relationship between ac initial susceptibility and temperature of nickel films with different thi...The temperature-driven spin reorientation transition of magnetron sputtered Ni/Si （111） systems has been studied. The relationship between ac initial susceptibility and temperature of nickel films with different thicknesses shows that the magnetization orientation changes from in-plane to out-of-plane with the increase of temperature. The temperature dependence of mugnetoelastic, magneto-crystalline, and magnetostatic anisotropies determines the direction of the reorientation transition. The temperature-driven spin reorientation transition is supported by Hall coefficient measurements which show that its temperature dependence is similar to that of susceptibility.展开更多
Ⅰ. INTRODUCTIONThere has been an increasing interest in spin glass ever since Cannela and Mydosh first observed the cusp of a.c. susceptibility in AuFe. For many years people have paid attention mainly to canonical s...Ⅰ. INTRODUCTIONThere has been an increasing interest in spin glass ever since Cannela and Mydosh first observed the cusp of a.c. susceptibility in AuFe. For many years people have paid attention mainly to canonical spin glasses, such as AuFe and CuMn, and considerable progress has been made in the study of such alloys. But many problems have still to be solved.展开更多
By changing the initial elements, we obtain high-quality samples of Al-Cu-Co decagonal quasicrystals with a wide range of composition. The sizes of the samples are typically several centimetres in length and 2-3 mm in...By changing the initial elements, we obtain high-quality samples of Al-Cu-Co decagonal quasicrystals with a wide range of composition. The sizes of the samples are typically several centimetres in length and 2-3 mm in diameter. These samples are identified to be decagonal single grains by powder x-ray diffraction method, and the composition is homogeneous confirmed by EDX and chemical method.展开更多
Some authors have studied a series of (Pd0.9965 Fe0.0035)1-xMnx alloys which exhibit distinctly different magnetic properties depending upon the Mn concentration x. It is attributed to the competing interaction in mag...Some authors have studied a series of (Pd0.9965 Fe0.0035)1-xMnx alloys which exhibit distinctly different magnetic properties depending upon the Mn concentration x. It is attributed to the competing interaction in magnetic systems, In general, for a large number of alloy systems with mixed ferro-antiferromagnetic interactions, the competition leads to a diversity of magnetic struetures and critical phenomena.展开更多
Systemic measurements show that there is no 3D to 2D crossover in the reduction of the superconducting transition temperature Tc in Nb thin films. This result is consistent with all previous measurements while it is c...Systemic measurements show that there is no 3D to 2D crossover in the reduction of the superconducting transition temperature Tc in Nb thin films. This result is consistent with all previous measurements while it is contrary to the prevailing understanding based on the interplay between proximity, localization, and lifetime broadening. Our study indicates that the decrease of Tc can be interpreted by the combined effects of electron-phonon coupling parameter λ and the defect scattering rate pw, being uniquely determined by their ratio λ/ρw. Other factors such as film thickness and irradiation do not produce additional effects beyond these two parameters.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2006CB91304)the Knowledge Innovation Program of the Chinese Academy of Sciences
文摘The grain size and surface morphology of sputtered Au films are studied by x-ray diffraction and atomic force microscope. For as-deposited samples the grain growth mechanism is consistent with the two-dimensional （2D） theory, which gives relatively low diffusion coefficient during deposition. Annealing process demonstrates the secondary grain growth mechanism in which the thickness dependence of grain boundary energy plays a key role. The surface roughness increases with the increase of grain size.
文摘The possibility of cooling a system from liquid helium temperature, 4.2 K, using a tunnel junction refrigerator is analysed. Calculations show that the device can be used over a wide temperature range from 4 K down to well below 1 mK with necessary cooling power. However, several serious difficulties must be overcome before the method can be used in low temperature laboratories.
基金supported by the National Natural Science Foundation of China (Grant No 10334080)
文摘The temperature-driven spin reorientation transition of magnetron sputtered Ni/Si （111） systems has been studied. The relationship between ac initial susceptibility and temperature of nickel films with different thicknesses shows that the magnetization orientation changes from in-plane to out-of-plane with the increase of temperature. The temperature dependence of mugnetoelastic, magneto-crystalline, and magnetostatic anisotropies determines the direction of the reorientation transition. The temperature-driven spin reorientation transition is supported by Hall coefficient measurements which show that its temperature dependence is similar to that of susceptibility.
文摘Ⅰ. INTRODUCTIONThere has been an increasing interest in spin glass ever since Cannela and Mydosh first observed the cusp of a.c. susceptibility in AuFe. For many years people have paid attention mainly to canonical spin glasses, such as AuFe and CuMn, and considerable progress has been made in the study of such alloys. But many problems have still to be solved.
基金Supported by National Natural Science Foundation of China under Grant No 100334080.
文摘By changing the initial elements, we obtain high-quality samples of Al-Cu-Co decagonal quasicrystals with a wide range of composition. The sizes of the samples are typically several centimetres in length and 2-3 mm in diameter. These samples are identified to be decagonal single grains by powder x-ray diffraction method, and the composition is homogeneous confirmed by EDX and chemical method.
文摘Some authors have studied a series of (Pd0.9965 Fe0.0035)1-xMnx alloys which exhibit distinctly different magnetic properties depending upon the Mn concentration x. It is attributed to the competing interaction in magnetic systems, In general, for a large number of alloy systems with mixed ferro-antiferromagnetic interactions, the competition leads to a diversity of magnetic struetures and critical phenomena.
基金Supported by the National Natural Science Foundation of China under Grant No 11104331the National Basic Research Program of China under Grant No 2011CB921702
文摘Systemic measurements show that there is no 3D to 2D crossover in the reduction of the superconducting transition temperature Tc in Nb thin films. This result is consistent with all previous measurements while it is contrary to the prevailing understanding based on the interplay between proximity, localization, and lifetime broadening. Our study indicates that the decrease of Tc can be interpreted by the combined effects of electron-phonon coupling parameter λ and the defect scattering rate pw, being uniquely determined by their ratio λ/ρw. Other factors such as film thickness and irradiation do not produce additional effects beyond these two parameters.
