Papers by Keyword: Sb

Abstract: Lateral MOSFET devices with a thin surface counter-doped layer using Sb and As with and without NO passivation have been fabricated and characterized. The results demonstrate that Sb and As counter-dope the interface without significant trap passivation while in combination with NO there is a superposition of both trap passivation and counter-doping related performance enhancement. In addition, by varying the counter doping level, a universal mobility characteristics of NO passivated devices has been identified.

Abstract: In this paper, the effects of Sb addition on heat-treated microstructure and mechanical properties of AZ61-0.7Si magnesium alloy were investigated. The results indicate that the solution heat treatment can modify the Chinese script shaped Mg2Si phase in the AZ61-0.7Si alloy. After solutionized at 420°C, the morphology of the Mg2Si phase in the AZ61-0.7Si alloy changes from the Chinese script shape to the short pole and block shapes, and the higher modification efficiency could be obtained for the alloy with the addition of 0.4 wt.%Sb. In addition, the effect of the solution heat treatment on the morphology of the Mg2Si phase can also result in the improvement of tensile and creep properties for the AZ61-0.7Si alloy. After solutionized at 420°C for 24h and followed by aging treatment at 200°C for 12h, the AZ61-0.7Si alloy exhibits higher tensile and creep properties than that of the as-cast alloy, and the properties improvement resulted from heat treatment, is more obvious for the AZ61-0.7Si alloy with the addition of 0.4 wt.%Sb.

Abstract: The effects of aging treatment on the damping capacities of ZA84-xSb alloys were studied. The results show that in the aging treatment process, because of following mainly reasons: (1) the dissolution of the ternary phases, (2) the increase of grain interfaces, (3) the increases of dislocation density, and (4) the micro deformations of matrix interfaces and the second phases, the damping capacity of ZA84-xSb magnesium alloys did not be reduced. On the contrary, whether at the low temperatures or high temperatures, its damping capacity is higher than as-cast alloy, which is of great significance for the application of ZA84-xSb magnesium alloys.

Abstract: The microstructure and impact toughness of in-situ Mg₂Si/Al-Si composites were studied in the different content of Sb. The results show that Sb can improve the microstructure and impact toughness of Mg₂Si/Al-Si composites. When the content of Sb is 0.4%, the morphology of primary Mg₂Si changes from dendrites to fine particles, the average size of Mg2Si particles is refined from 52μm to 25μm, and the impact toughness of the composites increases from 6.3572J/cm2 to 11.4394J/cm2. The improvement of impact toughness can be attributed to the fine-grain strengthening. However, excessive Sb is disadvantageous to the modification of the composites.

Abstract: The doping of Cu in the BaSi₂ films grown by molecular beam epitaxy (MBE) with various Cu concentrations for the suitability of the solar cells was studied in this paper. The main objective of the present work is to investigate and compare the carrier concentration of Cu-doped BaSi₂ films grown with different Cu Knudsen cell temperatures and qualify as a potential candidate for more efficient solar cells. The reflection high-energy electron diffraction (RHEED), X-ray diffraction (XRD) measurements and secondary ion mass spectroscopy (SIMS), were used to determine the structure, depth profile and composition of the grown samples. The electrical properties like resistivity as well as carrier concentration were measured by using a four point probe method and Van der Pauw technique, respectively. During the MBE growth, different temperatures for Cu Knudsen cell ranging from 800 to 1200 °C were chosen and the optimum growth condition for both heavily doped n-type as well as p-type in the MBE was investigated. In our previous work, the Al, Sb doped BaSi₂ were used as a potential candidate for the formation of pn-junction for solar cells, but the result was not encouraging one due to diffusion and segregation problems in the surface and BaSi₂/Si interface regions. In the present work n-type BaSi₂ layers with their dopant atoms uniformly distributed in the grown layers for the formation of high-quality of BaSi₂ pn-junction with single crystal nature were successfully developed. The realizations to develop cost effective and more efficient solar cells are inevitable for both terrestrial as well as space applications.

Abstract: The microstructure and wear resistance of in-situ Mg₂Si/Al-Si were studied in the different content of Sb. The result shows that when the content of Sb is 0.4%, the refining effect of primary Mg₂Si granules in Mg2Si/Al-Si composite is best. The shape of Mg₂Si turned into fine and even granules compared to the shape of Chinese character or treelike crystal before modification. At the same, the composite shows the best wear resistance and the loss of wear quality was reduced by 19%～37%. The improvement of the wear resistance by alloy elements is related to the modification of the Mg₂Si granules and enhancement of the matrix. The main wear mechanism of in-situ Mg₂Si/Al-Si composite is grain-abrasion.

Abstract: The paper researched the method of using the L-Cysteine to pre-reduction and using hydrid atomic fluorescence spectrometry to determining the As、 Sb 、Bi and Hg elements.In the preparation determination condition,the elements have a wide linear rangeand, the sample analysis results coincided with the recommended values. Detection limit of each element wereAs0.08ng／mL、Sb 0.06ng／mL、Bi 0.07ng／mL、Hg 0.004ng／mL。After nearly more than 100,000 pieces of the determination of geochemical samples, the sample have a good parallel.

Abstract: The microstructure and mechanical properties of aged Mg-5.5Al-1.2Y magnesium alloy with Sb addition are investigated by optical microscope, SEM and X-ray diffraction analyzer. The results show that with proper content of Sb addition,the microstructure of Mg-5.5Al-1.2Y magnesium alloy is refined obviously and high melting point intermetallic compounds Sb₃Y₅ and Mg₃Sb₂ are formed. Meanwhile, the β-Mg₁₇Al₁₂ phase is more distributed. With the increase of Sb addition, the mechanical properties of the alloy at room and elevated temperature increase at first, and then decrease. When the content of Sb is up to 0.5%, the values of tensile strength and elongation at room temperature, 150^ºC and 175^ºC are up to their maxima synchronously, 241MPa /16.84%, 198MPa/20.27.86% and 169MPa/21.21% respectively.

Abstract: The effect of Cd and Sb addition on the microstructural and mechanical properties of as-cast AZ31 alloys was investigated and compared. The results indicate that the difference of Sb and Cd in the microstructure and mechanical properties of as-cast AZ31 magnesium alloy is significant. Addition of 0.15%Sb (mass fraction) to AZ31 alloy can refine the matrix and β-Mg₁₇Al₁₂ phase but not form a new phase Mg₃Sb₂. Oppositely, by addition of 0.3-0.7% Cd to AZ31 alloy, Cd was dissolved into the AZ31 alloy, the phase composition did not change but was refined also. Accordingly, the Cd-refined AZ31 alloy exhibits higher tensile and impact toughness and Brinell hardness properties than the Sb- refined one. The difference of Sb and Cd in the mechanical properties is possibly related to the solid solution of Cd into the matrix and formation of Mg₃Sb₂ which has the same close-packed hexagonal structure as α-Mg.

Abstract: In this paper, the effects of Sb and RE on the solutionized microstructure and microhardness of Mg-6A1-1Zn-0.7Si magnesium alloy are investigated. The research results indicate that the solid solution treatment can result to the modification of Chinese script shaped Mg2Si phases in the microstructure of experimental alloy, and adding small amounts of RE and Sb can strengthen the modification efficiency. In addition, after the solid solution treatment at 420°C, the Mg-6A1-1Zn-0.7Si alloy added 0.4%Sb and 0.25%RE exhibits higher microhardness, but the effect of Sb and RE additions on the changing law between microhardness and solutionized time, is not obvious.