For intermetallic compound TiAl,the interatomic potentials in the Finnis-Sinclair model were constructed by empirically fitting to the properties of L10 TiAl tetragonal phase and the pressure-volume relations.In the c...For intermetallic compound TiAl,the interatomic potentials in the Finnis-Sinclair model were constructed by empirically fitting to the properties of L10 TiAl tetragonal phase and the pressure-volume relations.In the calculations of point defect properties of TiAl alloy with this potentials,it was shown that the thermal concentration of antisite defects was higher than that of other point defects.With similar formation energies,five possible interstitial configurations were stable.This model was consistent with the embedded atom method or embedded defect method and adequate for simulation of defects in TiAl alloy.展开更多
Nanostructured Fe_(40)Ni_(38)Mo_(4)B_(l8) prepared by crystallization technique has a microstructure of nanometer-sized fcc(Fe,Ni)solid solution crystallites embedded in a nanometer-thick amorphous matrix.The nanostru...Nanostructured Fe_(40)Ni_(38)Mo_(4)B_(l8) prepared by crystallization technique has a microstructure of nanometer-sized fcc(Fe,Ni)solid solution crystallites embedded in a nanometer-thick amorphous matrix.The nanostructured Fe_(40)Ni_(38)Mo_(4)B_(l8) obtained at 740K has the optimal soft magnetic properties.The maximal magnetic softening can be understood by considering the combination of the zero anisotropy and the lowest saturation magnetostriction.展开更多
ZnO/Fe_(2)O_(3) nanorod arrays(NRs)and ZnO/NiO nanotube arrays(NTs)are synthesized on Si substrates by using a facile two-step growth method.The absorption spectrum of the ZnO/Fe_(2)O_(3) NRs shows significant absorpt...ZnO/Fe_(2)O_(3) nanorod arrays(NRs)and ZnO/NiO nanotube arrays(NTs)are synthesized on Si substrates by using a facile two-step growth method.The absorption spectrum of the ZnO/Fe_(2)O_(3) NRs shows significant absorption in the visible light region.Their photocatalytic properties are evaluated by the degradation of methylene blue(MB).It is found that the ZnO/Fe_(2)O_(3) NRs display higher photocatalytic activity than the ZnO/NiO nanotube arrays under UV-vis light irradiation.This is most likely attributed to an effective separation of photoelectrons and holes.展开更多
The ceramic samples with nominal composition of La_(2/3)Ca_(1/3)Fe_(1-x)Mn_(x)O_(3)(0.01≤x≤0.20)were prepared by solid state reaction method.The effect of Fe doping on the Mn site was measured by the positron annihi...The ceramic samples with nominal composition of La_(2/3)Ca_(1/3)Fe_(1-x)Mn_(x)O_(3)(0.01≤x≤0.20)were prepared by solid state reaction method.The effect of Fe doping on the Mn site was measured by the positron annihilation technique and M'dssbauer spectroscopy.Upon doping,no appreciable structure change and electronic structure change in Mn-O plane were observed in the series of compounds.The M6ssbauer parameters show that the iron probe has stable 3+valance with the high spin state in all samples.Moreover,by examining the shape of the spectra,the tendency can be found that the isomer shift and quadruploe splitting increase with the increasing Fe+3 content.This phenomenon shows the local lattice distortion and the localization of d-electrons with the increasing Fe-doping content.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.59895150.
文摘For intermetallic compound TiAl,the interatomic potentials in the Finnis-Sinclair model were constructed by empirically fitting to the properties of L10 TiAl tetragonal phase and the pressure-volume relations.In the calculations of point defect properties of TiAl alloy with this potentials,it was shown that the thermal concentration of antisite defects was higher than that of other point defects.With similar formation energies,five possible interstitial configurations were stable.This model was consistent with the embedded atom method or embedded defect method and adequate for simulation of defects in TiAl alloy.
基金Supported in part by the National Natural Science Foundation of China under Grant No.59772039the State Key Laboratory of the Rapidly Solidified Alloys+1 种基金the Applied Magnetism Laboratory of the Education Ministrythe Natural Science Foundation of Gansu Province.
文摘Nanostructured Fe_(40)Ni_(38)Mo_(4)B_(l8) prepared by crystallization technique has a microstructure of nanometer-sized fcc(Fe,Ni)solid solution crystallites embedded in a nanometer-thick amorphous matrix.The nanostructured Fe_(40)Ni_(38)Mo_(4)B_(l8) obtained at 740K has the optimal soft magnetic properties.The maximal magnetic softening can be understood by considering the combination of the zero anisotropy and the lowest saturation magnetostriction.
基金Supported by the National Basic Research Program of China under Grant No 2007CB613302the National Natural Science Foundation of China under Grant No 50972002.
文摘ZnO/Fe_(2)O_(3) nanorod arrays(NRs)and ZnO/NiO nanotube arrays(NTs)are synthesized on Si substrates by using a facile two-step growth method.The absorption spectrum of the ZnO/Fe_(2)O_(3) NRs shows significant absorption in the visible light region.Their photocatalytic properties are evaluated by the degradation of methylene blue(MB).It is found that the ZnO/Fe_(2)O_(3) NRs display higher photocatalytic activity than the ZnO/NiO nanotube arrays under UV-vis light irradiation.This is most likely attributed to an effective separation of photoelectrons and holes.
基金Supported by the National Natural Science Foundation of China under Grant No.19805010by the Key-project of Chinese Academy of Sciences under contract KJ952-S1-416.
文摘The ceramic samples with nominal composition of La_(2/3)Ca_(1/3)Fe_(1-x)Mn_(x)O_(3)(0.01≤x≤0.20)were prepared by solid state reaction method.The effect of Fe doping on the Mn site was measured by the positron annihilation technique and M'dssbauer spectroscopy.Upon doping,no appreciable structure change and electronic structure change in Mn-O plane were observed in the series of compounds.The M6ssbauer parameters show that the iron probe has stable 3+valance with the high spin state in all samples.Moreover,by examining the shape of the spectra,the tendency can be found that the isomer shift and quadruploe splitting increase with the increasing Fe+3 content.This phenomenon shows the local lattice distortion and the localization of d-electrons with the increasing Fe-doping content.
