Pure potassium dihydrogen phosphate (KDP) crystals and KDP doped with L-alanine have been grown by slow evaporation technique at room temperature. Grown crystals have been characterized using powder X-ray diffraction,...Pure potassium dihydrogen phosphate (KDP) crystals and KDP doped with L-alanine have been grown by slow evaporation technique at room temperature. Grown crystals have been characterized using powder X-ray diffraction, (XRD), Energy Dispersive X-ray spectroscopy (EDX) and Fourier Transform Infrared spectroscopy (FTIR). The presence of L-alanine into pure KDP crystal was confirmed by FTIR and EDX spectra. Crystal structure has been studied by XRD. Pure KDP and L-alanine doped KDP crystals both possessed tetragonal structure. The transparency is found to increase with the increase of doping concentrations of the grown crystals as observed by UV-Vis spectra. A.C. electrical conductivity of grown crystals along the growth axis was carried out at various temperatures ranging from 35?C - 400?C. Dielectric constant and dielectric losses are measured as a function of temperature and this study reveals the contribution of space charge polarization. Crystal defects and surface morphology are studied by dissolution solvent technique and reveals the step growth mechanism for both pure and doped crystals.展开更多
AFM is used for forming silicon dioxide as a layer (mask) on the silicon wafer surface (100) during the cutting process in ambient atmosphere. The silicon dioxide is made through reaction of silicon and oxygen in the ...AFM is used for forming silicon dioxide as a layer (mask) on the silicon wafer surface (100) during the cutting process in ambient atmosphere. The silicon dioxide is made through reaction of silicon and oxygen in the atmosphere. As a result of the anisotropic behavior of single crystalline silicon, the etching rates in alkaline solution depend greatly on the various crystal orientations. The anisotropic etching behaviors in KOH solution and reasons of crystalline silicon are described. Effect of etching conditions such as etching temperature and KOH concentration of the alkaline solution on height of the micro-protuberances has been described.展开更多
为了提升电火花线切割(Wire cut Electric Discharge Machining,WEDM)加工后的TC4钛合金表面质量,减少表面重熔层厚度,采用不同浓度配比(1∶4、1∶6和1∶8)的HF-HNO_(3)酸蚀溶液对钛合金试件进行化学抛光处理。实验结果表明,HF-HNO_(3)...为了提升电火花线切割(Wire cut Electric Discharge Machining,WEDM)加工后的TC4钛合金表面质量,减少表面重熔层厚度,采用不同浓度配比(1∶4、1∶6和1∶8)的HF-HNO_(3)酸蚀溶液对钛合金试件进行化学抛光处理。实验结果表明,HF-HNO_(3)酸蚀溶液能使钛合金重熔层得到显著去除,表面微裂纹得到有效控制;当HF-HNO_(3)酸蚀溶液的浓度配比为1:6时,试件能获得最低的表面粗糙度和最大的表面粗糙度下降率,并且抛光前后钛合金表面元素含量发生了不同程度的变化,Ti、Al和V元素质量分数分别提高了21.5%、41.3%和13.2%,而O、C元素质量分数分别降低了82.5%和33.6%;HF-HNO_(3)酸蚀溶液可显著改善TC4钛合金试件电火花线切割加工后的表面缺陷。钛合金重熔层结构的主要成分与化学抛光后氧化膜的主要成分相似,但与氧化膜的结构不同,这对TC4钛合金试件表面质量提升具有重要意义。展开更多
文摘Pure potassium dihydrogen phosphate (KDP) crystals and KDP doped with L-alanine have been grown by slow evaporation technique at room temperature. Grown crystals have been characterized using powder X-ray diffraction, (XRD), Energy Dispersive X-ray spectroscopy (EDX) and Fourier Transform Infrared spectroscopy (FTIR). The presence of L-alanine into pure KDP crystal was confirmed by FTIR and EDX spectra. Crystal structure has been studied by XRD. Pure KDP and L-alanine doped KDP crystals both possessed tetragonal structure. The transparency is found to increase with the increase of doping concentrations of the grown crystals as observed by UV-Vis spectra. A.C. electrical conductivity of grown crystals along the growth axis was carried out at various temperatures ranging from 35?C - 400?C. Dielectric constant and dielectric losses are measured as a function of temperature and this study reveals the contribution of space charge polarization. Crystal defects and surface morphology are studied by dissolution solvent technique and reveals the step growth mechanism for both pure and doped crystals.
基金Sponsored by the Natural Science Foundation of China (Grant No.20271019), the Natural Science Foundation of Heilongjiang Province (Grant No.B200504) and the Education Department Foundation of Heilongjiang Province (Grant No.11511270).
文摘AFM is used for forming silicon dioxide as a layer (mask) on the silicon wafer surface (100) during the cutting process in ambient atmosphere. The silicon dioxide is made through reaction of silicon and oxygen in the atmosphere. As a result of the anisotropic behavior of single crystalline silicon, the etching rates in alkaline solution depend greatly on the various crystal orientations. The anisotropic etching behaviors in KOH solution and reasons of crystalline silicon are described. Effect of etching conditions such as etching temperature and KOH concentration of the alkaline solution on height of the micro-protuberances has been described.
文摘为了提升电火花线切割(Wire cut Electric Discharge Machining,WEDM)加工后的TC4钛合金表面质量,减少表面重熔层厚度,采用不同浓度配比(1∶4、1∶6和1∶8)的HF-HNO_(3)酸蚀溶液对钛合金试件进行化学抛光处理。实验结果表明,HF-HNO_(3)酸蚀溶液能使钛合金重熔层得到显著去除,表面微裂纹得到有效控制;当HF-HNO_(3)酸蚀溶液的浓度配比为1:6时,试件能获得最低的表面粗糙度和最大的表面粗糙度下降率,并且抛光前后钛合金表面元素含量发生了不同程度的变化,Ti、Al和V元素质量分数分别提高了21.5%、41.3%和13.2%,而O、C元素质量分数分别降低了82.5%和33.6%;HF-HNO_(3)酸蚀溶液可显著改善TC4钛合金试件电火花线切割加工后的表面缺陷。钛合金重熔层结构的主要成分与化学抛光后氧化膜的主要成分相似,但与氧化膜的结构不同,这对TC4钛合金试件表面质量提升具有重要意义。
