Functional Materials, 2016, том 23
http://dspace.nbuv.gov.ua:80/handle/123456789/114732
2024-03-28T23:56:38ZProfessor B.V.Grinyov - 60 years
http://dspace.nbuv.gov.ua:80/handle/123456789/121866
Professor B.V.Grinyov - 60 years
2016-01-01T00:00:00ZTime-resolved Ax-luminescence of NaI:Tl under electron pulse irradiation
http://dspace.nbuv.gov.ua:80/handle/123456789/121515
Time-resolved Ax-luminescence of NaI:Tl under electron pulse irradiation
Yakovlev, V.; Trefilova, L.; Alekseev, V.; Krasnov, V.
This paper studies spectral-kinetic properties of NaI:Tl cathodoluminescence registered in the region of Ax-band with maximum 425 nm within the time interval of 10⁻⁸-10⁻² s. Ax-luminescence of NaI:Tl crystal has been excited with an electron pulse (Ee = 0.25 MeV, t1/2 = 10 ns, W = 0.003...0.16 J/cm2) at temperatures in the range of 65-300 K. It has been found that the cathodoluminescence kinetics of NaI:Tl crystal at 425 nm has beside the exponential decay (τ = 235 ns at T = 295 K) also three more components: the fastest exponential decay (τ = 12 ns at T = 78 K), post-irradiation rise on a submicrosecond time scale at T≥128 K and slow exponential decay at T≥160 K. A model has been suggested according to which Ax-luminescence at 425 nm is caused by 11→1S0 electron transition of Tl+ ion. It has been explained that the fast decay and post-irradiated rise components are caused by ³P₁→¹P₁ and ³P₀→³P₁ electron transitions of Tl<m^>+ ion, respectively. The scintillation process in NaI:Tl has been discussed.
2016-01-01T00:00:00ZX-ray and photo-excited luminescence of ZnWO₄ nanoparticles with different size and morphology
http://dspace.nbuv.gov.ua:80/handle/123456789/121514
X-ray and photo-excited luminescence of ZnWO₄ nanoparticles with different size and morphology
Tupitsyna, I.A.; Maksimchuk, P.O.; Yakubovskaya, A.G.; Malyukin, Y.V.; Zvereva, V.S.; Vovk, O.M.
X-ray and photoluminescence of ZnWO₄ nanocrystals with controlled size and morphology: grains with diameter of 10-20 nm; rods with diameter of 10-20 nm and length of 200-250 nm produced by microwave hydrothermal method were studied. Red luminescence with λmax = 700 nm was found in the samples. The intensity of the red luminescence increases with decreasing of the ZnWO₄ nanoparticles size due to increase of concentration of oxygen vacancies and creation of distorted WO₆ centers. It was shown that reduction in the X-ray luminescence intensity with decrease of the ZnWO₄ nanoparticles size is due to creation of the distorted WO₆ centers which are the nonradiative relaxation channel competing with the self-trapped excitons.
2016-01-01T00:00:00ZPecularities of pore relaxation in nanoclusters
http://dspace.nbuv.gov.ua:80/handle/123456789/121513
Pecularities of pore relaxation in nanoclusters
Ratner, M.A.; Yanovsky, V.V.
Process of the relaxation of a cluster with an intrinsic pore was investigated for different phases of a cluster. Main parameters, determining pore dissolving time were found. In particular, it was shown that there exists critical temperature Tc, that depends on pore and cluster sizes. Below Tc nonequilibrium process does not destroy solid state of the cluster and pore life time increases sharply. Process of pore relaxation in this case is characterized by a free energy barrier.
2016-01-01T00:00:00Z