ANALYSIS OF HYDROGEN DIFFUSION FROM PROTON-EXCHANGED LAYERS IN LINBO3

Hydrogen profiles for proton-exchanged layers in Z-cut LiNbO3 were obtained by secondary ion mass spectrometry measurements after annealing at 400-degrees-C for times from 6 to 180 min. To fit the measured hydrogen profiles, it was necessary to use two separate Gaussian diffusion profiles which could be designated as a more slowly diffusing substitutional hydrogen on lithium sites and a more rapidly diffusing interstitial hydrogen. At 400-degrees-C, analysis leads to a substitutional hydrogen diffusion coefficient D(s) almost-equal-to 4.6 X 10(-12) cm2/s and an interstitial hydrogen diffusion coefficient D(i) almost-equal-to 1.5 x 10(-11) cm2/S.