Growth And Optical Performance Of LaCl₃:Pr

New halide scintillation crystal offers high light output,low theoretical energy resolution and fast decay time,has already aroused earthling attention due to its excellent performance.The excellent performance of LaCl₃:Ce crystal has been recognized by society,and LaCl₃:Pr crystal is similar as LaCl₃:Ce crystal in spatial structure.As for LaCl₃:Pr crystal,it occurs as a hexagonal structure with the space group of P63/m,which belongs to the intermediate vug.That proves to be the basis for useful laser systems.It is pity that the scintillation properties of LaCl₃:Pr crystal is disregardful.Though the study on LaCl₃:Pr crystal is keeping on the way,all of the researches are focusing on the mid-infrared solid-state laser.It is pity that the scintillation properties of LaCl₃:Pr3 crystal are disregardful.Therefore,in order to clarify the optical performance of LaCl₃:Pr crystal,we carry out the research on the growth and optical performance test of LaCl₃:Pr crystal.The main research work includes the following aspects:?1?A transparent LaCl₃:Pr single crystal without macroscopical defects was grown by vertical Bridgman method.The differential scanning calorimetry?DSC?shows that the melting point of LaCl₃:Pr crystal is about 841.5?,and finds suitable growth process parameters by repeated experiments.The temperature of the high temperature zone is set to 900?,the crucible descent rate is 0.3mm/h,and cooling rate is around 15? /h.We study the reason of crystal defects and improve the growth process parameters to avoid it.?2?The X-ray powder diffraction?XRD?pattern proves the crystal structure of LaCl₃:Pr is hexagonal with space group P63/m.The Optical Performance of a 0.7 at% Pr-doped LaCl₃ single crystal and 5 at% Pr-doped LaCl₃ single crystal has been tested respectively as followed:?a?The two kinds of LaCl₃:Pr crystal,0.7 at% Pr-doped and 5 at% Pr-doped,are lower than 30% in transmittance,and the transmittance at infrared wavelengths is about 75%.?b?The result of light output and energy resolution is not well.LaCl₃ Pr 0.7% single crystal only has a small peak in Waveform figure,and the energy resolution is about 42.5%.There is no result in LaCl₃ Pr 5% single crystal.?c?From the X-ray induced emission spectrum,it can be seen that the emission spectrum consists of three peaks at 330 nm,356 nm and 400 nm,respectively.And Waveform figure of two kinds of LaCl₃ Pr crystal is alike.?d?The UV excited photoluminescence spectrum of two kinds of LaCl₃ Pr crystal shows two dominated emission peaks,located at 265 nm and 290 nm,which is consistent with the X-ray induced emission spectrum,?e?Decay time of LaCl₃ Pr 0.7% single crystal were fitted to be about 14.5 ns for 335 nm,14.6 ns for 356 nm and 1.3 ns for 400 nm.And Decay time of LaCl₃ Pr 5% single crystal were fitted to be about 13.8 ns for 335 nm,14.6 ns for 356 nm and 0.97 ns for 400 nm.