The radial distribution of dopant (Cr, Nd, Yb, or Ce) in yttrium aluminum garnet (Y3Al5O12) single crystals grown by the micro-pulling-down method

Dopant distribution in yttrium aluminum garnet (YAG:Y3Al5O12) shaped crystal grown via the micro-pulling-down method depends primarily on the distribution coefficient (k0)(k0). The solid-favoring dopants (k0>1.0)(k0>1.0), Cr and Yb, concentrated in the central core of the crystal, while the liquid-favoring dopants (k0<1.0)(k0<1.0), Nd and Ce, concentrated in the rim. Secondary rare-earth oxide phases were sometimes segregated and crystallized circumferentially with Nd and Ce dopant. The dopant distribution profile was also controlled by the position of the melt entrance hole in the crucible shaper, which was confirmed by SIMPLER calculation. Segregation/distribution coefficients for Cr, Yb, Nd, and Ce in YAG were found to be 1.5, 1.01, 0.1, and 0.01, respectively.