DEPENDENCE OF TETRAGONAL PbWO4 LATTICE PARAMETERS ON SYNTHESIS
Jan Sykora 1,Michal Husak1 , Otto Jarolimek2
1 Department of Solid State Chemistry, Prague
Institute of Chemical Technology, Technická 5, 166 28
Prague 6, Czech Republic, e-mail:sykoraj@vscht.cz
2 Department of Physics, Technical University of
Liberec, Hálkova 6, 461 17 Liberec, Czech Republic
Keywords: PbWO4, lattice
parameters determination, PbO - WO3
The tetragonal phase of PbWO4 is the suitable material for construction of fast scintillation detectors [1] . Dependence of the lattice parameters of PbWO4 on the composition of the starting mixture of lead and tungstate oxides was studied [2].
14 samples with the Pb/W ratio 0.5 - 1.64 in mother liquid phase was prepared. In addition 6 other samples obtained from industrial production of PbWO4 was used for investigation. Powder diffraction patterns were measured on XRD 3000 Seifert diffractometer, CoK radiation and corundum as internal standard were used for lattice parameter determination. Only such reflections of PbWO4 were included which did not overlapped with reflections of other phases (WO3 and Pb2WO5) existing in the system.
The refined a and b values and the unit cell volume were
correlated with the Pb/W ratio in mother liquid phase. No
correlations were found. It seems no other phase from the PbO -
WO3 system is able to incorporate in crystals of PbWO4.