Gerasymov I. Growth of rare-earth pyrosilicates single crystals for scintillation applications

The thesis is dedicated to search for obtaining procedures, obtaining and characterization of bulk scintillation crystals based on gadolinium pyrosilicate. Undoped and cerium-, praseodymium-, lanthanum-, scandium-doped (codoped) crystals based on gadolinium pyrosilicate were grown by the Czochralski and TSSG methods for the first time. The structure of the crystals are determined. They belong to the three different polymorphs. The relationship between the type of polymorphic modifications and cationic composition of the compound is shown. The structure of a new crystalline modification of ?-Gd2Si2O7 is described, which previously was considered as noncharacteristic for a given compound. The optical, luminescent and scintillation properties of the obtained crystals were determined. It was established that all obtained gadolinium pyrosilicate crystals doped with cerium ions are very efficient scintillator with high light output, fast decay, low afterglow and high temperature stability of light yield at elevated temperatures.