Growth and morphology of neodymium or ytterbium doped calcium gadolinium yttrium oxoborate (Re∶Ca 4Gd x Y 1- x O(BO 3) 3(Re∶GdYCOB)Re =Nd,Yb; x =0-1)were systematically studied. Polycrystalline materials used for Re...Growth and morphology of neodymium or ytterbium doped calcium gadolinium yttrium oxoborate (Re∶Ca 4Gd x Y 1- x O(BO 3) 3(Re∶GdYCOB)Re =Nd,Yb; x =0-1)were systematically studied. Polycrystalline materials used for Re∶GdYCOB single crystals growth were synthesized by multistage solid phase reaction method.Re∶GdYCOB single crystals were grown by Czochralski technique.The pulling rates are 0.5-2mm/h and the rotation rates are 10-30r/min.Usually 65-75% polycrystalline materials can be transformed into good quality single crystals under our growth conditions. The structures of some as grown Re∶GdYCOB single crystals were measured by using a four circle diffractometer.The results measured show that the space group of the crystals is C 3 s Cm.The determined lattice constants of 8 at% Nd doped Ca 4YO(BO 3) 3 single crystal are a =0.8076nm, b =1.6020nm, c =0.3527nm , β =101.23°.展开更多
Pure and neodymium-doped gadolinium calcium oxoborate crystals of high quality were grown by the Czochralski method.The orientation of crystal was precisely determined,and the samples for measurements were prepared.Th...Pure and neodymium-doped gadolinium calcium oxoborate crystals of high quality were grown by the Czochralski method.The orientation of crystal was precisely determined,and the samples for measurements were prepared.Through synchrotron x-ray topography and high-resolution x-ray diffractometry,the twin structure was discovered.Some properties such as the figure of merit value,and dielectric,piezoelectric,and elastic constants were meausured along with a discussion of the anisotropy of the laser properties.展开更多
Large GdCa4O(BO3)3 crystal has been grown by the Czochralski method.The quality of GdCa4(BO3)3 crystal was assessed by white-beam synchrotron radiation topography.It has been found that there is a sub-grain boundary i...Large GdCa4O(BO3)3 crystal has been grown by the Czochralski method.The quality of GdCa4(BO3)3 crystal was assessed by white-beam synchrotron radiation topography.It has been found that there is a sub-grain boundary in the GdCa4O(BO3)3 crystal.The boundary divides the large GdCa4O(BO3)3 crystal into two individuals.Due to the misorientation between the two individuals,the image shifts can be observed in the synchrotron topopraphs.Based on the misorientation determined by high resolution X-ray diffractometer,the image shifts were calculated for several reflections.The calculations are in agreement with the measurements from the topogrphs very Well.In addition,the formation mechanism of sub-grain boundary is discussed.2001 Elsevier science B.V.All rights reserved.展开更多
The growth detects in Nd:YCa4O(BO3)3(Nd:YCOB) crystals were investigated by transmission synchrotron topography.It was found that growth striations were the primary defects in Nd:YCOB crystals.Grown-in dislocations.mo...The growth detects in Nd:YCa4O(BO3)3(Nd:YCOB) crystals were investigated by transmission synchrotron topography.It was found that growth striations were the primary defects in Nd:YCOB crystals.Grown-in dislocations.mosaic blocks and inclusions were also obsered in the crystals.The effect of temperature field on the formation of growth defects in the crystals was discussed.展开更多
文摘Growth and morphology of neodymium or ytterbium doped calcium gadolinium yttrium oxoborate (Re∶Ca 4Gd x Y 1- x O(BO 3) 3(Re∶GdYCOB)Re =Nd,Yb; x =0-1)were systematically studied. Polycrystalline materials used for Re∶GdYCOB single crystals growth were synthesized by multistage solid phase reaction method.Re∶GdYCOB single crystals were grown by Czochralski technique.The pulling rates are 0.5-2mm/h and the rotation rates are 10-30r/min.Usually 65-75% polycrystalline materials can be transformed into good quality single crystals under our growth conditions. The structures of some as grown Re∶GdYCOB single crystals were measured by using a four circle diffractometer.The results measured show that the space group of the crystals is C 3 s Cm.The determined lattice constants of 8 at% Nd doped Ca 4YO(BO 3) 3 single crystal are a =0.8076nm, b =1.6020nm, c =0.3527nm , β =101.23°.
文摘Pure and neodymium-doped gadolinium calcium oxoborate crystals of high quality were grown by the Czochralski method.The orientation of crystal was precisely determined,and the samples for measurements were prepared.Through synchrotron x-ray topography and high-resolution x-ray diffractometry,the twin structure was discovered.Some properties such as the figure of merit value,and dielectric,piezoelectric,and elastic constants were meausured along with a discussion of the anisotropy of the laser properties.
文摘Large GdCa4O(BO3)3 crystal has been grown by the Czochralski method.The quality of GdCa4(BO3)3 crystal was assessed by white-beam synchrotron radiation topography.It has been found that there is a sub-grain boundary in the GdCa4O(BO3)3 crystal.The boundary divides the large GdCa4O(BO3)3 crystal into two individuals.Due to the misorientation between the two individuals,the image shifts can be observed in the synchrotron topopraphs.Based on the misorientation determined by high resolution X-ray diffractometer,the image shifts were calculated for several reflections.The calculations are in agreement with the measurements from the topogrphs very Well.In addition,the formation mechanism of sub-grain boundary is discussed.2001 Elsevier science B.V.All rights reserved.
文摘The growth detects in Nd:YCa4O(BO3)3(Nd:YCOB) crystals were investigated by transmission synchrotron topography.It was found that growth striations were the primary defects in Nd:YCOB crystals.Grown-in dislocations.mosaic blocks and inclusions were also obsered in the crystals.The effect of temperature field on the formation of growth defects in the crystals was discussed.
