Kinetics of Nd³⁺ luminescent complexes in CCl₄–GaCl₃ solutions

In order to create a low-toxic and cheap liquid laser medium, carbon tetrachloride solutions activated by Nd³⁺ were prepared. The concentration of Nd³⁺ in CCl₄–GaCl₃–Nd³⁺ solutions reaches 1 mol/l, whereas the lifetime of the excited state of Nd³⁺ does not exceed 80 μs and the quantum yield of Nd³⁺ luminescence is less than 0.3. The spectral-luminescent properties of CCl₄–GaCl₃–Nd³⁺ solutions, the kinetics of formation and quenching of luminescent Nd³⁺ complexes are considered. The rate of Nd³⁺ complexation increases with increasing [GaCl₃] : [Nd³⁺] ratio. The limitation of the lifetime of the excited state of Nd³⁺ is due to the overlap of the absorption band of the CCl₄–GaCl₃–Nd³⁺ solution with the luminescent band 4F3/2 → 4I15/2 in the wavelength range of 1840 – 1870 nm.