An influence of transition metal ions impurities on the luminescence of Li2Zn2(MoO4)(3) crystals

The optimal conditions for Li2Zn2(MoO4)(3) crystal growth were selected on the basis of corrected phase diagram. Large undoped and activated by transition metal ions (Cu, Cr, Fe, Ti) crystals were grown upon these conditions. Charge state and structural position of transition metal ions were determined by EPR method. Investigations of luminescence shown that the luminescence with lambda = 388 nm is observed for undoped crystals at room temperature. The luminescence lifetime is described by two exponential components, with relaxation times tau(1) = 2 ns and tau(2) = 6 ns. The luminescence with lambda = 560 nm and lifetime tau = 100 nm is observed as for undoped, so as for activated by transition metal ions crystals at 77 K. Besides, the luminescence intensity with lambda = 560 nm depends on nature and concentration of transition metal ions. It is supposed, that cation vacancies, which ensure the charge compensation of the impurity transition metal ions, are responsible for the low-temperature luminescence.