The effects of additive SnO2 (0.4wt.%), with and without SiO2 (0.02wt.%) and/or CaO (0.04wt.%), on the microstructure and magnetic properties of Mn-Zn ferrites were reported. The results reveal that SnO2 on its own in...The effects of additive SnO2 (0.4wt.%), with and without SiO2 (0.02wt.%) and/or CaO (0.04wt.%), on the microstructure and magnetic properties of Mn-Zn ferrites were reported. The results reveal that SnO2 on its own increases the initial permeability (μi) slightly, but SnO2 with SiO2 and/or CaO decreases the values of μi. However, ferrites with SnO2 additions have reduced power losses. The separate contributions of hysteresis loss and eddy current loss to the total power loss show that SnO2 (with or without SiO2 and/or CaO) doping increases the hysteresis loss slightly, but SnO2 doping alone reduces the eddy current loss significantly (～14%). The additions of SiO2 or CaO further decrease the eddy current loss, and by interaction of SnO2-CaO-SiO2, the eddy current loss is reduced by more than 20%. These magnetic and microstructural effects were discussed in terms of the additive-impurity interaction, the existence of grain boundary phases, and the effective bulk and grain boundary resistivities of the ferrites.展开更多
A new conductive grease was synthesized using a nanometer powder,i.e.,Sb doped SnO2(ATO),as an additive.The typical properties of this new conductive grease were investigated in detail.The results indicate that ATO ca...A new conductive grease was synthesized using a nanometer powder,i.e.,Sb doped SnO2(ATO),as an additive.The typical properties of this new conductive grease were investigated in detail.The results indicate that ATO can dramatically improve the dropping point and reduce contact resistance.The tribological properties of the new conductive grease were investigated using the MFT-R4000 reciprocating friction and wear tester.The tribol-test results indicate that ATO can dramatically improve the tribological properties of the grease.When the ATO concentration is 0.1wt%,the grease demonstrates the best friction reduction properties;when the concentration is 0.5wt%,the grease demonstrates the best anti-wear properties.The worn surfaces were observed and analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy,and the friction mechanisms for the new conductive grease are proposed.The excellent tribological properties of the new conductive grease are attributed to the mechanical effect of ATO,and the film formed by Sn and Sb elements or metallic oxide deposited on worn surfaces during the friction process.展开更多
The physico-chemical properties of cesium doped SnO2 nanocrystals synthesized by wet chemical method have been investigated. Scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive X-ray ana...The physico-chemical properties of cesium doped SnO2 nanocrystals synthesized by wet chemical method have been investigated. Scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive X-ray analysis （EDAX）, inductively coupled plasma （ICP）, atomic absorption spectroscopic （AAS） analyses, UV-vis-NIR spectral studies and dielectric studies were carried out for both pure SnO2 and cesium doped SnO2 nano-samples. All samples of SnO2 did not show any metallic cluster, but the sample containing cesium as a dopant displayed significant activity. The products formed were chloride and water representing a competitive advantage from the stand point of environmental protection.展开更多
文摘The effects of additive SnO2 (0.4wt.%), with and without SiO2 (0.02wt.%) and/or CaO (0.04wt.%), on the microstructure and magnetic properties of Mn-Zn ferrites were reported. The results reveal that SnO2 on its own increases the initial permeability (μi) slightly, but SnO2 with SiO2 and/or CaO decreases the values of μi. However, ferrites with SnO2 additions have reduced power losses. The separate contributions of hysteresis loss and eddy current loss to the total power loss show that SnO2 (with or without SiO2 and/or CaO) doping increases the hysteresis loss slightly, but SnO2 doping alone reduces the eddy current loss significantly (～14%). The additions of SiO2 or CaO further decrease the eddy current loss, and by interaction of SnO2-CaO-SiO2, the eddy current loss is reduced by more than 20%. These magnetic and microstructural effects were discussed in terms of the additive-impurity interaction, the existence of grain boundary phases, and the effective bulk and grain boundary resistivities of the ferrites.
基金supported by Hundreds Talent Program of Chinese Academy of Science.
文摘A new conductive grease was synthesized using a nanometer powder,i.e.,Sb doped SnO2(ATO),as an additive.The typical properties of this new conductive grease were investigated in detail.The results indicate that ATO can dramatically improve the dropping point and reduce contact resistance.The tribological properties of the new conductive grease were investigated using the MFT-R4000 reciprocating friction and wear tester.The tribol-test results indicate that ATO can dramatically improve the tribological properties of the grease.When the ATO concentration is 0.1wt%,the grease demonstrates the best friction reduction properties;when the concentration is 0.5wt%,the grease demonstrates the best anti-wear properties.The worn surfaces were observed and analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy,and the friction mechanisms for the new conductive grease are proposed.The excellent tribological properties of the new conductive grease are attributed to the mechanical effect of ATO,and the film formed by Sn and Sb elements or metallic oxide deposited on worn surfaces during the friction process.
文摘The physico-chemical properties of cesium doped SnO2 nanocrystals synthesized by wet chemical method have been investigated. Scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive X-ray analysis （EDAX）, inductively coupled plasma （ICP）, atomic absorption spectroscopic （AAS） analyses, UV-vis-NIR spectral studies and dielectric studies were carried out for both pure SnO2 and cesium doped SnO2 nano-samples. All samples of SnO2 did not show any metallic cluster, but the sample containing cesium as a dopant displayed significant activity. The products formed were chloride and water representing a competitive advantage from the stand point of environmental protection.
