Optical spectroscopy study of Cr³⁺ ion in NaMg₃Al(MoO₄)₅ crystal

Abstract

Electron absorption, excitation and emission spectra have been measured for Cr 3+ ion-doped NaMg 3 Al(MoO 4 ) 5 crystal in the temperature range from 9 to 300 K. The sharp lines of the 2 E-4 T 2 emission and broadband 4 T 2 -4 A 2 luminescence from strong and weak crystal field Cr 3+ sites as well as their temperature dependencies were observed. Below 200 K, Cr 3+ ion pairs are detected. The local structure of Cr 3+ surroundings is discussed in terms of the spectroscopic results and the crystal field parameters Dq, B and C of the Cr 3+ ion are derived. The Huang -Rhys, S, and breathing phonons, ħω, parameters are reported. The use of the studied crystal as a laser material is briefly analyzed.

Ultra-broadband near-infrared luminescence of ordered–disordered multi-sited Cr3+ in La3Ga5.5Nb0.5O14:Cr3+

“…1 In particular, trivalent chromium ion (Cr 3+ ) has been commonly used as the optical activator in a large number of tunable laser mediums. Cr 3+ ion could exhibit broadband emission in various hosts, such as BeAl 2 O 4 , 2 b-Ga 2 O 3 , 3 LiCaAlF 6 , 4 ScBO 3 , 5 Mg 2 SiO 4 , 6 NaMg 3 Al(MoO 4 ) 5 , 7 and MWO 4 (M ¼ Mg, Zn, Cd), 8 with band locating at either 600-900 nm [2][3][4][5] or 900-1300 nm. [6][7][8] Since the performance of the laser system is inuenced by the emission band width of the gain media, a broader emission band would result in a narrower output laser pulse or more transmission channels for optical amplier.…”

“…Cr 3+ ion could exhibit broadband emission in various hosts, such as BeAl 2 O 4 , 2 b-Ga 2 O 3 , 3 LiCaAlF 6 , 4 ScBO 3 , 5 Mg 2 SiO 4 , 6 NaMg 3 Al(MoO 4 ) 5 , 7 and MWO 4 (M ¼ Mg, Zn, Cd), 8 with band locating at either 600-900 nm [2][3][4][5] or 900-1300 nm. [6][7][8] Since the performance of the laser system is inuenced by the emission band width of the gain media, a broader emission band would result in a narrower output laser pulse or more transmission channels for optical amplier. 9 Thus, it presents new challenges for developing tunable luminescent materials with broader near-infrared (NIR) emission band.…”

Effects of synthesis method on cation distribution and optical properties of Co/Cr co-doped MgGa2O4 nanoparticles

“…When doped with a small amount of Co and Cr (x=0.02, y=0.01), these samples exhibit an intense peak at 370 nm and a relative weak absorption band at 500-700 nm. The peak at 370 nm can be due to the absorption of tetrahedral Cr 3+ ions, and the band at 500-700 nm is assigned to the combination of the absorption of tetrahedral Co 2+ and octahedral Cr 3+ ions [20][21][22].…”

Study on Spectra and Mg-O Bond-Length of NaMg₃Al(MoO₄)₅: Cr³⁺ Crystal at Low Temperature

“…Therefore we can use the same value of N (0.958) obtained above and adjust the bond length Mg-O to fit the spectra at 9 K. The fitted results are shown in Table .2 (Mg Site). The fitted bond length of Mg-O is 2.0528 Å at 9 K. At 295 K and 105 K, the bond lengths of Mg-O are 2.0548 Å and 2.0536 Å, respectively [7]. Using these values, we can fit the equation and obtain the coefficients a = 4.9958×10 -6 , b = -6.8674×10 -9…”

“…Since the spectral characteristics of transition metal ions are strongly dependent on the local environment, the optical properties will changed with the crystal sites substituted by Cr 3+ [4][5]. Single crystals of NaMg 3 Al(MoO 4 ) 5 :Cr 3+ were grown and the absorption and emission spectra were measured by K. Hermanowicz et al [6][7].…”