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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×80mm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543nm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218nm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。
Using the Czochralski method, a chemical composition ratio of 100: 99.85: 0.30 of BeO: Al2O3: MnO and a secondary material process are adopted, a temperature gradient of solid-liquid interface of about 60 DEG C and a growth rate of 1 mm / h are selected Process parameters, the Mn2 +: BeAl2O4 crystals were successfully grown with Mn2 + ions doped, no bubbles, no clouds and no core and a size of about 45 mm × 80 mm. The excitation and fluorescence spectra of the crystals at different positions were measured. Along the crystal growth direction, the crystal color gradually become darker. The fluorescence band centered at 543nm was observed in the Mn2 +: BeAl2O4 fluorescence spectrum, which is attributed to the 4T1 (4G) → 6A1 (6S) transition of Mn2 +. An excitation peak of 218 nm was observed in its excitation spectrum due to the charge transfer transition of the electrons from the Mn2 + ground state to the conduction band. From the green emission of Mn2 + ions, it can be inferred that Mn2 + is in the tetrahedral field of the crystal, which replaces the lattice sites of Be2 + ions in the crystal. The effective segregation coefficient of Mn2 + in BeAl2O4 crystal is less than 1 from the excitation intensity and color change of crystal in different parts.