Suppression mechanism of millisecond afterglow in CsI:Tl crystals by Eu²⁺ impurity

• Date: 2009
• Main Authors: Kudin, A.M., Shkoropatenko, A.V., Ovcharenko, N.V., Alekseev, V.D., Trefilova, L.N., Shpilinskaya, A.L.
• Format: Article
• Language: English
• Published: НТК «Інститут монокристалів» НАН України 2009
• Series: Functional Materials
• Subjects: Characterization and properties
• Online Access: http://dspace.nbuv.gov.ua/handle/123456789/137899
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Suppression mechanism of millisecond afterglow in CsI:Tl crystals by Eu²⁺ impurity // A.M. Kudin, A.V. Shkoropatenko, N.V. Ovcharenko, V.D. Alekseev, L.N. Trefilova, A.L. Shpilinskaya // Functional Materials. — 2009. — Т. 16, № 3. — С. 275-278. — Бібліогр.: 16 назв. — англ.

The causes of millisecond afterglow in Csl:Tl crystals have been considered. The two afterglow components with about 5 ms and about 60 ms characteristic time at RT have been shown to be related to the trap disruption at 190 and 215 K. The thermostimulated luminescence peak at 215 K is of extrinsic nature and is associated most probably with barium cations in the form of single dipoles Ba²⁺-Vc⁻. In contrast to Ba²⁺, introduction of Eu²⁺ cations results in the afterglow attenuation. The aggregation of Eu²⁺-Vc⁻ dipoles in a quenched sample has been found to occur during almost 10 min at RT. The afterglow suppression mechanism in Csl:Tl,Eu crystals consists in that not only europium ions but also other Me²⁺ type impurities are involved in the aggregation process. After the solid solution decomposition and metastable aggregate formation, not millisecond but more durable afterglow is observed in the crystals within the second and minute time ranges.