Optical properties of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>center in crystalline<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Al</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">O</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Ultraviolet optical absorption, emission, and excitation spectra are presented for 14-MeV neutron-irradiated high-purity crystalline ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$. Low-temperature polarized excitation spectra for the 3.8-eV luminescence correlated well with polarized absorption at 4.8 eV (both polarizations) and 5.4 eV ($\stackrel{\ensuremath{\rightarrow}}{\mathrm{E}}\ensuremath{\perp}\stackrel{\ensuremath{\rightarrow}}{\mathrm{c}}$). These optical properties compare favorably with those predicted using wave functions from an earlier pointion calculation for the ${\mathrm{F}}^{+}$ center by La, Bartram, and Cox. The 4.8- and 5.4-eV absorption bands are assigned to the $1A\ensuremath{\rightarrow}1B$ and $1A\ensuremath{\rightarrow}2A$ transitions, respectively, of the ${F}^{+}$ center and the 3.8-eV luminescence is assigned to the $1B\ensuremath{\rightarrow}1A$ transition. The $1A\ensuremath{\rightarrow}2B$ transition could not be conclusively identified, but preliminary evidence suggests it occurs near 6.3 eV. Similar absorption and emission bands are observed following energetic-proton and ${\mathrm{Al}}^{+}$ bombardment. Other uv optical properties are presented, including the quantum efficiency, lifetime, and temperature dependence of the emission.

Ҳали таржима қилинмаган