EXCIMER MOLECULAR COMPLEXES $XeO^{+}$ IN RARE GAS CRYOMATRICES

Author Institution: B. Verkin Institute for Low Temperature Physics and Engineering, Ukrainian Academy of SciencesSpecific features of luminescence spectrum, potentials and mechanisms of $XeO^{*}$ excimer complex formation in rare-gas crystals are investigated. The measurements are carried out by the cathodoluminescence spectroscopy method on solid solutions of O and Xe in Kr, Ar and Ne matrices. Analysis of the spectroscopic constants of the $2\Sigma^{+} - 1^{2}\Sigma^{+}$ transition gives the principal parameters of the state $1^{1}\Sigma^{+}$ in different matrices. The effect of polarization properties of the crystalline surroundings of the molecule both on potential depth and position of the intersection with the ground dissociative term of the excimer moleccule $XeO^{2}$ is established. It is shown that the formation of $XeO^{5}$ molecules is realized through a multistage process controlled by the mechanism of exciton-induced reactions. At the first stage, the exciton trapping by $O_{2}$ impurity centers leads to a dissociation of the molecules followed by an emergence of the oxygen atoms from the initial cell. The excitation of O and Xe atoms stimulates their accelerated diffusion, promoting a stabilization of O and Xe in neighbouring lattice positions. At the final stage, the trapping of the matrix excitons by the Xe or O atoms causes a formation of $Xe0^{\ast}$ centers. Peculiar features of the mechanism of exciton-induced reactions in rare-gas cryomatrices are discussed