Cr3+掺杂的Cd3Al2Ge3O12光谱特性及晶场参数计算

采用高温固相法合成了Cd₃Al₂Ge₃O₁₂：Cr³⁺多晶材料，利用X射线衍射对其结构进行了分析，通过Cr³⁺的室温吸收光谱、室温和77K发射光谱分别对其光谱特性和晶场参数进行了分析和计算.结果表明：在450 nm的蓝光激发下，Cd₃Al₂Ge₃O₁₂：Cr³⁺室温发 关键词： 3Al₂Ge₃O₁₂：Cr³⁺')" href="#">Cd₃Al₂Ge₃O₁₂：Cr³⁺ 荧光光谱 晶场参数 可调谐激光

Spectral characteristics and crystal field parameters of the Cr3+ doped Cd3Al2Ge3O12

Polycrystalline Cd₃Al₂Ge₃O₁₂：Cr³⁺ was synthesized by high temperature solid-state method. Its crystal structure was analyzed by X-ray diffraction. Based on its absorption spectrum at room temperature and the emission spectra at room temperature and 77K， the spectral properties were investigated and the crystal field parameter was calculated. The results show that under the excitation of 450nm light， the emission spectrum of Cd₃Al₂Ge₃O₁₂：Cr³⁺ at room temperature mainly consists of three broad bands with a weak R line. The three broad bands correspond to ⁴T₁→⁴A₂， ²T₂→⁴T₂， and ⁴T₂→⁴A₂ transitions of Cr³⁺， respectively. The broad band emissions weaken and the R line becomes stronger and sharper at low temperature. The calculated results showed the crystal field strength D_q/B=2.32， Stokes displacement ΔE_S=1919cm^-1 and Huang-Rhys factor S=5.58， which indicates that Cr³⁺ in Cd₃Al₂Ge₃O₁₂ garnet are located in a weak crystal field strength and the coupling between the electrons and the phonons is strong， The distance ΔE between ⁴T₂ zero phonon energy level and ²E energy level is only 326.5cm^-1， which is beneficial to the output of Cr³⁺ tunable laser.