应用提拉法技术,采用BeO:Al2O3:MnO摩尔比为100:99.85:0.30的化学组分配比和二次化料过程,选用约60 ℃的固液界面温度梯度与1 mm/h生长速度等工艺参量,成功地生长出了Mn2＋离子掺杂、无气泡、无云层和核心、尺寸约45 mm×80 mm的粉红色Mn2+:BeAl2O4晶体。测定了不同部位晶体的激发光谱与荧光光谱。沿着晶体生长方向,晶体颜色逐步变深。在Mn2+:BeAl2O4荧光谱中观测到发光中心为543 nm的荧光带,这归属于Mn2+的4T1(4G)→6A1(6S)能级跃迁所产生。在其激发光谱中观测到218 nm的激发峰,这归属于电子从Mn2+基态到导带的电荷转移跃迁所致。从Mn2+离子的绿色发射情况可以推断Mn2+处于晶体中四面体场中,它取代晶体中Be2+离子的格位。从不同部位晶体的激发峰强度与颜色变化可以得到Mn2+在BeAl2O4晶体中的有效分凝系数小于1。

The pink Mn²⁺-doped BeAl₂O₄crystals in the size of 45 mm×80 mm without bubble, cloud and cores have been grown by Czochralski (CZ) technique under the technical conditions of choosing BeO:Al2O3:MnO raw chemical compositions in molar ratio of 100:99.85:0.3, taking twice melting process of the raw materials and using ～60 ℃ temperature gradient of solid-liquid interface and 1 mm/h growth rate. The excitation and absorption spectra of the Mn2+:BeAl2O4 from different parts were recorded. It is found that the pink color of the crystal becomes deeper along the Mn2+ growing direction. An emission band at 543 nm is observed in the emission spectra of Mn2+:BeAl2O4 crystal, which attributes to the electron transition of 4T1(4G)→6A1(6S) level. An excitation band at 218 nm is also observed in the excitation spectra, which corresponds to the electron transition from the ground state to the conduction band (CB). It can be deduced from the green emission that the Mn2+ substitutes Be2+ in BeAl2O4 crystal to form the tetrahedron. From the excitation intensity and color of different parts, it can be convinced that the effective distribution coefficient of Mn2+ ion in BeAl2O4 crystal is less than 1.