TY  - JOUR
AU  - Pustovarov, Vladimir
AU  - Ogorodnikov, Igor
AU  - Kozlov, Alexander
AU  - Isaenko, L. I.
TI  - A luminescence-optical spectroscopy study of Rb<sub>2</sub>KTiOF<sub>5</sub> single crystals
JO  - Optical materials
VL  - 80
SN  - 0925-3467
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - PUBDB-2019-00217
SP  - 47 - 56
PY  - 2018
N1  - © Elsevier B.V. 
AB  - Large single crystals of Rb<sub>2</sub>KTiOF<sub>5</sub> (RKTF), grown by slow solidification method, were studied (7–400 K) for various types of optical and radiation effects. The optical absorption spectra, the parameters of the Urbach rule at 293 K (σ = 0.24 and  = E<sub>U</sub>105 meV), the low-temperature reflection spectra (T = 7 K, E = 3.7–22 eV) were determined. The luminescence spectra (1.2–6.2 eV) and luminescence decay kinetics are studied upon excitation by a nanosecond electron beam (PCL), ultraviolet and vacuum ultraviolet light (PL), or X-rays radiation (XRL). PL excitation spectra under selective photoexcitation by synchrotron radiation (E = 3.7–22 eV, T = 7 K), temperature dependences of the intensity of steady-state XRL in different emission bands, as well as thermoluminescence (7–400 K) are studied. In the visible spectral region, we detected three luminescence bands that were attributed to radiative annihilation of intrinsic excitons (2.25 eV), recombination-type luminescence (2.1 eV) and luminescence of higher TiOF<sub>5</sub> complexes (1.9 eV). The exponential component with lifetime of about 19 μs was revealed in the PCL decay kinetics at 2.25 eV. The low-energy onset of the intrinsic host absorption  E<sub>c</sub>= 3.55 eV was determined on the basis of the experimental data obtained. Spectra of optical constants were calculated by the Kramers-Krönig method, the energy of the onset of the interband transitions  E<sub>g</sub>= 4.2 eV was determined, and the main peaks of the optical spectra were identified.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000435053600007
DO  - DOI:10.1016/j.optmat.2018.04.027
UR  - https://bib-pubdb1.desy.de/record/418130
ER  -