Spectral hole burning in emerald

Effects of low magnetic fields in transient spectral hole-burning of the R1-line in emerald, Be3Al2Si6O18:Cr(III)

“…The AE3/2 level (2 A A) is the lower-lying Kramers doublet in the 4 A 2 ground state. We note here that previously reported absorption spectra of lab grown emeralds with higher Cr 3þ concentrations were often significantly broader (C inh % 5 cm À1 ) [7]. Moreover, natural emeralds show even broader widths C inh due to the presence of a range of impurities: for example we have measured C inh % 40 cm À1 for the R-lines in Brazilian emerald with a low Cr 3þ concentration but containing Fe 2þ and water.…”

“…Persistent spectral hole-burning in the R-lines ( 2 E 4 A 2 excitations) of Biron-lab emerald has been investigated previously but transient holes appeared to be very shallow and thus were not reported [7]. Emeralds grown by the Chatham laboratories are of high optical quality and appear to be free of water, alkalis and Fe 2þ /Fe 3þ impurities.…”

“…The spectroscopy of emerald has been the subject of numerous investigations over the years [1][2][3][4][5][6][7]. Emerald is the green variety of the ring silicate beryl, Be 3 Al 2 Si 6 O 18 .…”

Nuclear magnetic resonance study of the relaxation mechanisms of the 9Be, 27Al, and 29Si nuclei in Cr3+-doped Be3Al2Si6O18 crystals

“…The spectroscopy of emerald has been the subject of numerous investigations [4][5][6][7][8][9]. The parameters of the quadrupole Hamiltonians of the 9 Be and 27 Al nuclei in an emerald single crystal have been determined [10][11][12]; the quadrupole parameters of 9 Be and 27 Al in pure Be 3 Al 2 Si 6 O 18 crystals at room temperature were studied by Brown and Williams [11], who reported values of e 2 qQ/h ¼0.504 MHz and Z¼0.09 and e 2 qQ/h¼3.093 MHz and Z¼0, respectively.…”

“…The parameters of the quadrupole Hamiltonians of the 9 Be and 27 Al nuclei in an emerald single crystal have been determined [10][11][12]; the quadrupole parameters of 9 Be and 27 Al in pure Be 3 Al 2 Si 6 O 18 crystals at room temperature were studied by Brown and Williams [11], who reported values of e 2 qQ/h ¼0.504 MHz and Z¼0.09 and e 2 qQ/h¼3.093 MHz and Z¼0, respectively. In addition, various electron paramagnetic resonance (EPR) studies of emerald have been reported, including an antiferromagnetic exchange coupling study [8], the spin-lattice relaxation of Cr 3 + EPR at 22.2 GHz in the temperature range 1.5-45 K [13], a study of the EPR line-widths of the inter-doublet [14], and Cr 3 + and Fe 3 + EPR studies [15][16][17].…”