Concentration dependence of Ni2+ luminescence in MgO
|Nina Mironova-Ulmane 2, Ilmo Sildos 3, Janis Grabis 1|
1. Riga Technical University, Miera 34, Riga, Latvia
It is known that nickel ions doped magnesium oxide MgO:Ni2+ is the excellent potential as tunable infrared laser in the 1300-1500 nm. However in order to optimize MgO:Ni for the best operation and evaluate its potential, it is necessary to have data on the luminescence as a function of temperature and concentration of nickel ions.
We present results of luminescence spectra of Ni2+ ions for single crystals MgO and ceramics preparation from nanosized MgO:Ni. The single crystals MgO:Ni2+ in this investigation were grown by the chemical transport reaction methods and by melting. The ceramics MgO:Ni fabricated from nanopowders which received by evaporation of raw power in a radio-frequency plasma. The luminescence spectra with concentration of Ni cNi= 0,5%; 1% and 5 % single-crystals was studied in the range 460-1500 nm which includes all d-d electronic transition in ions Ni2+ at the temperatures from 10 to 300K. Luminescence spectra of MgO:Ni consist of three broad band. The band at 12500 cm-1 is related to the 1E2(D)→3A2g(F) electrical dipole transition, the band at 18000 cm-1 is related to the 1T2g(D)→3A2g(F) electrical dipole transition whereas the band at 8000 cm-1 is related to the 3T2g(D)→3A2g(F) magnetically dipole transition. The intensity of luminescence of green and red band decreases when the temperature increases. Besides, the integral intensity of band in infrared luminescence depends strongly on the cNi and excitation wavelength. In the region of the concentration where we do not observe infrared luminescence of exchange-coupled of Ni2+ pairs, the infrared luminescence intensity does not depend on measurement temperature. At higher cNi can see luminescence of Ni2+ pairs, but where the number of the exchange-coupled pairs is relatively small, the infrared luminescence intensity of the zero-phone line for the single Ni ions remains constant below 70K and decrease exponentially above 100 K.
Presentation: oral at E-MRS Fall Meeting 2005, Laser Ceramic Symposium, by Nina Mironova-Ulmane
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-05-20 11:58 Revised: 2009-06-07 00:44