Growth method of high-temperature phase lanthanum borosilicate crystal and use

A growth method of a high-temperature phase lanthanum borosilicate crystal, wherein the high-temperature phase lanthanum borosilicate crystal is a β-La1-yLnyBSiO5 crystal prepared by a high-temperature flux method;

• a composite flux system is (La1-yLny)BO3—LiMoO4—SiO2—B2O3, and (La1-yLny)BO3, LiMoO4, SiO2, and B2O3 in the system have molar percentages of x1, x2, x3, and x4, respectively;
• 0<x1<0.3, 0.7≤x2<1, 0<x3<0.3, x1+x2+x3=1, x1:x4=2:1 to 4:1,
• wherein a phase transition of the β-La1-yLnyBSiO5 crystal is suppressed by controlling a microscopic crystal structure of LaBSiO5 through a doping ion Ln3+, wherein the doping ion Ln3+ has a doping concentration of y, 0.02≤y≤0.25, and wherein the β-La1-yLnyBSiO5 crystal is stabilized to room temperature without the phase transition;
• wherein the β-La1-yLnyBSiO5 crystal has a trigonal system structure, a space group of P3121, and a unit cell parameters a=b;
• α=β=90°, γ=120°, Z=3;
• wherein the (La1-yLny)BO3 has a raw material comprising La2O3, Ln2O3, H3BO3, and Li2CO3, and wherein the LiMoO4 has a raw material comprising Li2CO3 and MoO3, and wherein the B2O3 has a raw material of H3BO3;
• and
• wherein crystal growth is conducted at 700° C. to 1100° C., with a constant cooling rate, and the constant cooling rate is in a range of 0.5° C./day to 600° C./day, wherein after the crystal growth is completed, an annealing rate is 240° C./day to 800° C./day, and wherein the β-La1-yLnyBSiO5 crystal is grown with seed crystals at a crystal rotation rate of 5 rpm to 20 rpm.