The invention provides a method for growing large-sized rare-earth-doped
barium yttrium fluoride single crystals. The method comprises the following steps: in a
heating furnace, putting polycrystals of {xReF3+(1-x)YF3} and BaF2 into a
crucible according to a
mass ratio, vacuumizing, and introducing
argon gas into the
heating furnace successively, wherein the
mass ratio of {xReF3+(1-x)YF3} to BaF2 is 2 to 1 and x is 0-100%; controlling the
heating power by a
temperature control instrument to melt the polycrystals, performing heat exchange by flowing of a liquid surface in the
crucible and the gas in the furnace to form an axial
temperature difference, and forming a radial
temperature difference of temperature on a wall of the
crucible and temperature in the center of the crucible to cause
natural convection of a melt; fixing BaY2F8 seed crystals to a
seed crystal rod by a
platinum chuck, and lowering the seed crystals to be contacted with the melt for
fluoride crystal growth; when
fluoride crystals grow to have set sizes, annealing, cooling to the
room temperature at a speed of 20 DEG C / hour, adjusting the rotary speed and the
heating power, separating the crystals from the melt until the
crystal growth is ended, and annealing in the crucible to obtain the large-sized
fluoride crystals. The method solves the problems of negative growth factors of difficulty for
crystal growth, a large amount of air bubbles in the crystals and the like caused by poor flowability of the fluoride melt.