Growth of highly sensitive thermoluminescent crystal α-Al2O3:C by the temperature gradient technique

In this work, an α-Al2O3:C crystal with highly sensitive thermoluminescence was directly grown by the temperature gradient technique (TGT) using Al2O3 and graphite powders as raw materials. The optical and luminescent properties and the dosimetric characteristics of the crystal were investigated. An as-grown α-Al2O3:C crystal shows a single glow peak at 462 K and a blue emission peak at 415 nm. The thermoluminescence (TL) response of the crystal shows a linear–sublinear–saturation characteristic. In the dose range from 5×10−6 to 10 Gy, the α-Al2O3:C crystal shows excellent linearity, and saturation was observed at about 30 Gy. The sensitivity of the crystal decreases as the heating rate increases.