Isomorphism of titanium in natural minerals

A new stable radiation center in quartz

“…An experimental study of the correlation of the aluminum center concentration with the physico-chemical mineralformation parameters (Balitskiy et al, 1966) made it possible to use this center successfully for solving certain ore deposit geology problems Shcherbakova et al, 1976) and problems in penological structures . The use of the titanium electron center, which arises as the result of the capture of an electron by Ti+4, replacing a silicon (Bershov, 1970), for these same purposes has been reported. The radiation electron center _ (so-called "E-center") has found application in the field of paleodosimetry (Moiseyev and Rakov, 1975).…”

Electron paramagnetic resonance and the thermoluminescence emission mechanism of the 280°C peak in natural andalusite crystal

“…The temperature at which the EPR spectra of Ti 3 + disappear may be a measure of the stabilization energy. In the investigated minerals [22], it occurred in the range of 150-500 1C.…”

“…An investigation of a large number of naturally occurring minerals, formed under different genetic conditions performed by Bershov [22] and Bershov et al [23] showed that tetravalent titanium is usually isomorphously incorporated in their structure. However, Bershov also confirmed the formation of trivalent titanium electron center under ionizing radiation.…”

Mineralogy and mineral chemistry of quartz: A review

“…Likewise, very little is known about the local structural environment of Fe 2+ in quartz (Gressey et al, 1993;Schofield et al, 1995;Di Benedetto et al, 2009), because the magnetic properties of Fe 2+ with oxygen neighbours preclude its EPR observation at conventional Xband frequencies (Weil, 1994). S1; Bershov, 1970;Isoya and Weil, 1979;Weil, 1984;Bailey et al, 1992;Bailey and Weil, 1992a,b). This S1; Wright et al, 1963;Rinneberg and Weil, 1972;Weil, 1984;Matyash et al, 1987;Isoya et al, 1988;Weil, 1991, 1992).…”

“…Titanium is a typical trace impurity in quartz and isovalently substitutes as Ti 4+ for Si 4+ in the SiO 4 tetrahedra. The Ti 4+ in the diamagnetic [TiO 4 ] 0 centre can be transformed to the paramagnetic [TiO 4 ] – centre during irradiation at low temperatures (Table S1; Bershov, 1970; Isoya and Weil, 1979; Weil, 1984; Bailey et al , 1992; Bailey and Weil, 1992a,b). This [TiO 4 ] – centre is unstable above 120 K and, similar to the [GeO 4 ] – centres, can capture diffusing M + ions (H + , Li + , Na + ) to form charge compensated [TiO 4 /M + ] 0 centres (Table S1; Wright et al , 1963; Rinneberg and Weil, 1972; Weil, 1984; Matyash et al , 1987; Isoya et al , 1988; Bailey and Weil, 1991, 1992).…”