Dopant segregation in rare earth doped lutetium aluminum garnet single crystals grown by the micro-pulling down method

Nd, Ho, Er, and Tm doped lutetium aluminum garnet (LuAG) single crystals were grown using the micro-pulling down (μ-PD) method. The crystals were produced from the melts containing 3 mol% of the dopants. The axial and radial dopant distribution were measured by electron probe micro analysis. Nd3+ and Ho3+ ions concentrated in the rim (k0<1) and the radial concentration showed concave curvature. k0 is the segregation coefficient of the dopant with respect to the given host phase. In the case of Er3+ and Tm3+ ions, the k0 value is considered to be nearly 1 and the radial dopant distribution profiles were almost flat.

► Rare earth doped LuAG crystals were grown by the micro-pulling down method.
► Axial and radial dopant segregation were investigated.
► Ionic radii of dopants are important to determine segregation coefficients.