By flux method,potassium tantalate niobate crystals with 46%Nb contents were prepared.In this material 90°a-type domains with(011)and(01ī)walls were observed by a transmission electron microscope,and the nature ...By flux method,potassium tantalate niobate crystals with 46%Nb contents were prepared.In this material 90°a-type domains with(011)and(01ī)walls were observed by a transmission electron microscope,and the nature of fringe patterns associated with these domain walls was analysed.According to the extinction rules for the domain walls,the displacement vector R along<01ī>direction can be determined.Finally,using a selected area electron diffraction method,we examined the crystallographic character of these 90°domains and defined the ratio of lattice parameters c to a.展开更多
The dislocations in lithium tetraborate crystal have been investigated by means of synchrotron radiation white beam topography in BSRL(Beijing Synchrotron Radiation Laboratory).The Burgers'vectors of these disloca...The dislocations in lithium tetraborate crystal have been investigated by means of synchrotron radiation white beam topography in BSRL(Beijing Synchrotron Radiation Laboratory).The Burgers'vectors of these dislocations are determined by their vanishing conditions.Both screw and edge dislocations exist in the specimen.展开更多
基金Supported by the National Natural Science Foundation of China。
文摘By flux method,potassium tantalate niobate crystals with 46%Nb contents were prepared.In this material 90°a-type domains with(011)and(01ī)walls were observed by a transmission electron microscope,and the nature of fringe patterns associated with these domain walls was analysed.According to the extinction rules for the domain walls,the displacement vector R along<01ī>direction can be determined.Finally,using a selected area electron diffraction method,we examined the crystallographic character of these 90°domains and defined the ratio of lattice parameters c to a.
文摘The dislocations in lithium tetraborate crystal have been investigated by means of synchrotron radiation white beam topography in BSRL(Beijing Synchrotron Radiation Laboratory).The Burgers'vectors of these dislocations are determined by their vanishing conditions.Both screw and edge dislocations exist in the specimen.
