Intrinsic Luminescence of the Undoped Glasses of (CaO-Ga2O3-GeO2) System |
| B.V. Padlyaka, O.M. Borduna and P.P. Buchynskiib aDepartment of Physics, Ivan Franko State University, 50 Dragomanov Str., Lviv 290005, Ukraine bScientific and Industrial Amalgamation "Karat", 202 Stryiska Str., Lviv 290031, Ukraine |
| Received: July 23, 1998; revised version February 2, 1999 |
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| For the first time the intrinsic luminescence in the undoped (CaO-Ga2O3-GeO2) glasses with different composition has been found and investigated in the 80รท300 K temperature range. The new glasses of high chemical purity and optical quality with stoichiometric composition similar to that in calcium-gallium- germanium garnet (Ca3Ga2Ge3O12), trigonal Ca-gallogermanate (Ca3Ga2Ge4O14), and Ca3Ga2O6 crystals were obtained by the high-temperature synthesis method. The luminescence and photoexcitation spectra analysis, supported by EPR spectroscopy data, yields the following results: (i) the UV-excited non-elementary broad emission band with maxima at roughly 500 nm and 420 nm in the (CaO-Ga2O3-GeO2) glasses is due to recombination of ensemble of the transient hole O- centres; (ii) the emission bands with maxima at nearly 380 and 710 nm, which were distinctly revealed in glasses with the Ca3Ga2Ge4O14 and Ca3Ga2O6 compositions, are assigned to the luminescence of UV-induced electron centres of two different types. Possible models of the luminescence centres in (CaO-Ga2O3-GeO2) glass network are discussed. |
| DOI: 10.12693/APhysPolA.95.921 PACS numbers: 42.70.Ce, 78.60.-b, 76.30.Mi |