Study of effect of thermal annealing on crystalline perfection of bismuth germanate single crystals grown by low thermal gradient Czochralski method

Abstract

Bismuth germanate single crystals containing low angle and

Studies on the growth, optical, thermal and dielectric aspects of a proton transfer complex – Dimethyl amino pyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP) crystals for non-linear optical applications

“…The FWHM (full width at half maximum) values of the main peak and the peak due to very low angle (tilt angle i.e., the misorientation angle between the two crystalline regions on both sides of the structural boundary 61 arc min) boundary are respectively 23 arc s and 37 arc s. The half widths as well as the peak separation are within a minute of arc and shows that the crystal quality is reasonably good. The very low angle boundary obtained for this solution grown specimen may be attributed to the segregation of solvent which was entrapped within the crystal during growth and manifests as a very low angle grain boundary during the growth process in a similar way that Si impurities were segregated and form as very low angle boundary as observed by HRXRD and confirmed by secondary ion mass spectrometry (SIMS) in bismuth germanate (BGO) crystals [21].…”

The influence of Mn-doping on the nonlinear optical properties and crystalline perfection of tris(thiourea)zinc(II) sulphate crystals: Concentration effects

“…Although these values are very small, they indicate that the heavy compressive stress due to heavy doping (20 mol% Mn in the growth medium) leads to grain boundaries in the crystal. These results indicate that when the concentration of the dopant is higher, the Mn could not occupy the interstitial positions but quite likely most of them seem to be segregated at the boundaries as observed in our earlier studies by secondary ion mass spectrometry (SIMS) on bismuth germanate (BGO) crystals wherein the Si impurities were found to segregate along the structural grain boundaries [24]. The higher values of FWHM for the two boundaries (77 and 180 arc sec) indicate that the quality of these regions is also not up to the mark.…”

Studies on the growth and characterization of benzimidazole single crystals—vertical Bridgman technique

“…Therefore, it is essential to remove such boundaries. As observed in our earlier studies on bismuth germanate (BGO) single crystals [11] and the recent studies on lithium niobate (LiNbO 3 ) single crystals [12,13], post growth thermal annealing with slow heating and cooling rates led to remove such grain boundaries very effectively and thereby enhance the crystalline perfection.…”