Thermoluminescence properties of double potassium yttrium fluorides singly doped with Ce3+, Tb3+, Dy3+ and Tm3+ in response to image and image irradiation

The thermoluminescence (TL) properties of yttrium fluorides K2YF5 and KYF4 singly doped with Ce3+, Tb3+, Dy3+ or Tm3+ have been studied in the range from 30 °C to 500 °C after image or image irradiation. It has been found that K2YF5 doped with 5.0 at% Ce3+, K2YF5 doped with 1.0 at% Tb3+ and KYF4 doped with 5.0 at% Tb3+ show TL sensitivity of the same order as that of the well known TLD-100 (LiF:Mg,Ti) phosphor. Strongly different TL response to image or image irradiation has been found for Tb3+ doped K2YF5 crystals. The TL mechanism in these phosphors is discussed by taking into account the TL emission spectra from irradiated samples, which are identical to the emission spectra of the appropriate doping rare earth ions, and the kinetics parameters obtained with the method of various heating rates.