Emission spectra of MgSO4 : Dy, MgSO4 : Tm and MgSO4 : Dy,Mn phosphors

MgSO4:Dy, MgSO4:Tm and MgSO4:Dy,Mn thermoluminescence (TL) phosphors have b een prepared and their emission spectra were measured using a linear heater and optical multichannel analyzer. Emission bands at about 480, 580 and 66 0 nm of MgSO4 doped with Dy were observed in three dimension (3D) glow curv e. Emission bands about 360, 460, and 650 nm were observed in a 3D glow cur ve of MgSO4 doped with Tm. The emission spectra of MgSO4:Dy and MgSO4:Tm ar e attributed to the characteristic emission wavelengths from transitions of Dy3+ and Tm3+ respectively. The results show that the structures of traps in matrix materials determine the activation energy distribution and dopant energy levels of rare earth ions are related with the emission spectrum wa velengths of sulfate phosphors. The intensities of the glow peaks in both b ands at about 480 and 580 nm in MgSO4 doped Dy and Mn were dramatically red uced in comparison with that of MgSO4 doped Dy except above 300 degrees C. It means that the trapping structures of MgSO4 :Dy phosphor has greatly bee n altered by the co-dopant Mn but no change is observed in wavelengths of t he emission spectra. (C) 2000 Elsevier Science Ltd. All rights reserved.