The nature of luminescence of KI and KI-Na crystals at low temperature deformation after natural decrease in the symmetry of the lattice

Abstract

The X-ray luminescence spectra at low temperature (90K) uniaxial deformation were researched for KI and KI-Na crystals, that were stored for more than 10 years. The following regularities were observed: firstly, the intensities of the intrinsic emission bands at 3.3 eV (π) and 4.1 eV ( σ ) become equal in com- parison with freshly grown crystals; and secondly, with an increase in the degree of low-temperature uniaxial deformation, a gradual shift of the emission spectra occurs in two directions: the luminescence maximum at 3.3 eV shifts towards short wavelengths, the final position is fixed at 3.9 eV, which prac- tically merges with σ-luminescence; the radiation maximum at 3.0 eV (Ex-radiation) is shifted toward long wavelengths, the final position which is fixed at 2.8 eV. Thus, low temperature uniaxial deformation leads to the separation of the emission spectra at 3,3 eV(π) → 3,9 eV and 3.0 eV ( Ex ) → 2,8 eV, which are interpreted by the separation of weak → on and weak → strong exciton configurations , respectively.

Recommended Citation

Shunkeyev, K.; Zhanturina, N.; Myasnikova, L.; Sergeyev, D.; Aimaganbetova, Z.; Sagimbaeva, Sh.; Barmina, A.; and Ubaev, Zh. (2018) "The nature of luminescence of KI and KI-Na crystals at low temperature deformation after natural decrease in the symmetry of the lattice," Eurasian Journal of Physics and Functional Materials: Vol. 2: No. 3, Article 8.
DOI: https://doi.org/10.29317/ejpfm.2018020308