Mn激活无水芒硝在真空紫外光激发下的发光特性

Luminescence Properties of Thenardite Activated with Mn Under Vacuum Ultraviolet Excitation

在空气中900℃温度下,将纯天然无水芒硝(Na2SO4)和MnCl2的混合粉末900℃加热20 min后,迅速骤冷至室温制备了Na2SO4∶Mn发光材料,并测量了其在室温中真空紫外光激发下的光致发光谱。实验结果表明,在172 nm激发下的发射光谱由峰值位于在592 nm处的宽带谱构成,所得到的宽带谱归属于Mn2+的3d电子组态内4T1→6A1的辐射跃迁。红色发光监测得到的激发光谱分为两类:峰值位于165,233 nm处的基质吸收带和位于191,275 nm处的Mn2+的吸收带。MnCl2掺杂的质量分数在0.1%～0.4%范围内,随着Mn掺杂量的增加,Mn激活无水芒硝(Na2SO4∶Mn)的发射光谱强度相应增强,质量分数达到0.3%后出现浓度猝灭现象。

Na2SO4∶Mn phosphors were prepared by heating pure natural thenardite with MnCl2 at 900 ℃ for 20 min in air.Their photoluminescence（PL） spectra were investigated under vacuum ultraviolet（VUV） at room temperature.The results show the emission spectrum under 172 nm excitation consists of a broad band with a peak at 592 nm,which can be attributed to the 4T1→6A1 transition in the 3d shell of Mn2＋.The excitation spectrum obtained by monitoring the red luminescence divides into two parts： absorption bands of Mn2＋（191 nm and 275 nm） and host absorption bands（165 nm and 233 nm）.The relative emission efficiency increase with the mass fraction of MnCl2 in 0.1%~0.4% range,and the concentration quenching occurs at 0.3% Mn contents.