Spectral and kinetic characteristics of CdI2 and CdI2:Pb scintillators

Abstract

We have studied the effect of lead dopant on the optical absorption, photoluminescence, and x-ray luminescence spectra, and the scintillation characteristics of CdI 2 at room temperature. The crystals for the study were grown by the Stockbarger-Bridgman method. Activation of CdI 2 from the melt by the compound PbI 2 leads to the appearance in the absorption spectra in the near-edge region of an activator band at 395-405 nm, which is interpreted as an A band connected with electronic transitions from the 1 S 0 state to the 3 P 1 levels in the Pb 2+ ion. For x-ray excitation, CdI 2 :Pb 2+ crystals with optimal dopant concentration (~1.0 mol%) are characterized by a light yield with maximum in the 570-580 nm region that is an order of magnitude higher than for CdI 2 crystals in the 490-500 nm band. For α excitation, the radioluminescence kinetics for cadmium iodide is characterized by a very short (~0.3 nsec) rise time and fast decay of luminescence, with τ 1 ≈ 4 nsec and τ 2 = 10-76 nsec. Depending on the conditions under which the crystals were obtained, the fast component fraction is 95%-99%. The crystal is characterized by a similar scintillation pulse in the case of excitation by x-ray pulses. The radioluminescence pulse shape for CdI 2 :Pb in the decay stage is predominantly exponential, with luminescence decay time constants τ 1 ≈ 10 nsec and τ 2 = 200-250 nsec. This system is characterized by low afterglow, at the level for the Bi 4 G 3 O 12 scintillator. We have demonstrated the feasibility of using CdI 2 :Pb as a scintillator for detecting α particles.

Vapor phase growth and properties of mixed layered Pb1-xCdxI2 semiconductors

“…Heterogeneous solid solutions of Pb1-xCdxI2 are characterized by intensive photo-and Xluminescence at room temperature and high radiation resistance, while it opens up a possibility of using these materials for the production of high efficient rapid-action non-cooled scintillation detectors of X-and γradiation [1,2]. In [3], the possibility of using CdI2 crystals with an optimal impurity concentration of Pb ~ 1.0 mol.% as a scintillator for the registration of α-particles was shown. Studies of PbI2 nanostructures with a Cd content of up to 7.5 % have shown that they are a promising material for optoelectronic devices and ionizing radiation detectors.…”

“…Most of the published works are devoted to the study of the properties of Pb1-xCdxI2 solid solutions grown from melt the Bridgman-Stockbarger technique [1,3] and grown from solutions [4]. The growth of Pb1-xCdxI2 crystals from the vapour phase and their properties have been insufficiently studied.…”

Voltage assisted magnetic switching in Co50Fe50 interdigitated electrodes on piezoelectric substrates

“…5 The proposed concept relies on strain-mediated magnetoelectric coupling by combining the inverse piezoelectric and the magnetostrictive effect: the direction of the magnetization of a ferromagnetic particle can thus be controlled by a bias voltage applied across piezoelectric leads supporting the particles. 5 The proposed concept relies on strain-mediated magnetoelectric coupling by combining the inverse piezoelectric and the magnetostrictive effect: the direction of the magnetization of a ferromagnetic particle can thus be controlled by a bias voltage applied across piezoelectric leads supporting the particles.…”

Recombination processes in europium-doped cadmium iodide crystals

“…Pulsed scintillation of an unactivated crystal at room temperature showed a fast (τ 1 ≈ 4 nsec) and slow (τ 2 = 10-76 nsec) stage of emission decay [9]. The fraction of the fast component was ~98%.…”

“…The luminescence intensity increases and the maximum shifts to the range 540-560 nm as the temperature is lowered to 85 K. Activation of CdI 2 with a homologous anionic dopant of Cl or Br has little effect on the light yield and spectral parameters of CdI 2 at low or high temperature [2]. Doping CdI 2 with Pb 2+ , Sn 2+ , Eu 2+ , Mn 2+ , Cu + , and Ag + does modify the spectral properties of the compound and produces effective luminophores [2][3][4][5][6][7][8][9] and photochromic materials [10].…”