ESR dosimetric properties of talc and zircon

Two silicate minerals talc (Mg3Si4O10(OH)2) and zircon (ZrSiO4) with different crystal lattice structures were subjected to ESR dosimetric studies. Zircon shows anisotropic ESR signals at gxx = 2.0168, gyy = 2.0076 and gzz = 2.0033, which have been identified as a hole-center associated with Y3+ substituted at Zr4+ sites. Other characteristic signals were observed and identified. The ESR signal at g = 2.0033 showed positive response to γ-irradiation at 110 Gy and is suitable for use in dosimetry and dating of natural zircons. Talc (a magnesium sheeted silicate) exhibits ESR derivative spectrum characterized by the presence of Fe3+ at g = 4.28 and the hf-sixtet Mn2+ signals. This is due to the possible substitution of Fe3+ and Mn2+ in the Mg2+ octahedral sites, respectively. The enhancement of the Mn2+ sixtet by γ-irradiation increases the area occupied by the signals that makes it difficult for use with dosimetric applications.