Growth of beta barium borate (β-BaB2O4) thin films on alpha barium borate (α-BaB2O4) substrates

Crystalline β-BBO thin films have been successfully prepared on (0 0 1)-oriented Sr2+-doped α-BBO substrates using liquid phase epitaxy and pulsed laser deposition techniques. The films were characterized by X-ray diffraction and X-ray rocking curve (XRC). The present results manifest that the β-BBO thin films grown on Sr2+-doped α-BBO substrates have larger degree of orientation f-value and smaller XRC FWHM than the ones grown on other reported substrates. Compared with other substrates, α-BBO has the same UV cutoff and the similar structure to β-BBO. These results reveal that α-BBO single crystal may be a promising substrate proper to the growth of β-BBO films.