Effect of electronic energy loss and irradiation temperature on color-center creation in LiF and NaCl crystals irradiated with swift heavy ions

Abstract

LiF and NaCl crystals were irradiated at 8 K and 300 K with various light and heavy ions ͑C, Ti, Ni, Kr, Sm, Au, Pb, and U͒ of kinetic energy between about 50 and 2600 MeV, providing electronic energy losses from 0.7 to 26.4 keV/nm. A cryostat installed at the beamline allowed in situ absorption spectroscopy and thermostimulated luminescence ͑TSL͒ measurements from 8 K upward. Creation of electron and hole color centers is analyzed as a function of irradiation temperature, fluence, and thermal and optical bleaching. Anion interstitials ͑I and H centers͒ were only observed in crystals irradiated at 8 K. These defects are unstable and disappear in the temperature range 10-100 K. For heavy ions ͑Au, U͒, the F-center accumulation efficiency at low fluences is larger at 8 K than at room temperature. The opposite effect is observed for light ions ͑C, Ti, Ni͒. The results are discussed within the frame of transient heating influencing separation or annealing of point defects. − are charged anion molecules; X int − is a charged anion on an interstitial position; H A1 and H A2 are H centers next to an impurity A 1 and A 2 , respectively; nF is a F-center cluster.

Color center creation in LiF crystals irradiated with Xe, Kr and N ions: Dependence on fluence and beam current density

“…Heavy ion induced damage in LiF and other alkali halides can be described by a nanosize core region with defect aggregates and a larger halo of several tens of nanometers with color centers [1][2][3]. The defect creation in alkali halides is determined by electronic excitations (excitons, electrons and holes) [3][4][5].…”

Effect of inter-atomic Auger processes on relaxation of electronic vacancies at deep levels of highly ionized atoms in swift heavy ion tracks

“…[3,4]. In this case numerical simulations can give principle information about major processes governing relaxation of electronic subsystem in SHI tracks.…”

Effect of swift heavy ion on structural and optical properties of highly transparent zinc oxide films

“…Thermal spike model says that: SHI transfers the energy to free electron, these free electron transfer energy to lattice, and at cooling the atoms are displaced from their position due to which track is produced [14,15]. Thus, the SHI modifies the properties of any material by creating defects [16], stress and strain in the structure [17]. Therefore, in the present paper, SHI irradiation has been used to create stress and defect for modifying the structural and optical properties of ZnO film grown by the sol-gel spin-coating technique.…”