Temperature Dependence of the Widths and Positions of the R and N Lines in Heavily Doped Ruby

Abstract

The widths and positions of the R and N lines in heavily doped ruby have been measured at temperatures from 13° up to 450°K. The results for the temperature dependence of the linewidths are explained in terms of microscopic strains, Raman scattering of phonons by the impurity ions, and direct phonon processes. The results for the lineshifts with temperature are due to the absorption and emission of virtual phonons. A Debye model of phonons is used with different effective phonon distributions for the linewidth and lineshift processes. Also the effective phonon distribution for the broadening of pair (N) lines is different from that for the broadening of single ion (R) lines.

Carbonate stability in the Earth's mantle: A vibrational spectroscopic study of aragonite and dolomite at high pressures and temperatures

“…These heaters were coupled to a 110 V variable transformer and a temperature controller' temperatures were measured with a Pt-Pt13% Rh thermocouple cemented with silver paint to the diamond, and were stable to + 3 K. One of the primary difficulties of such externally heated high pressure studies is the relaxation of pressure which occurs on heating and the measurement of pressure at high temperature. To determine the pressure, we used thermal corrections for the temperature-induced shift in the ruby fluorescence to correct the ruby peak positions to their 300 K values [Powell et al, 1966;.Munro et al, 1985]. We note that, despite the weakening 0• the ruby fluorescence at high temperature, we were able to measure ruby peaks in all our high temperature samples.…”

Direct investigation of inhomogeneous spectrum broadening in Nd^3+:Gd_xY_1−xVO_4 series crystals

“…3 depicts, the full width at half-maximum (FWHM) clearly increases as the temperature increases from 77 to 300 K. Because of the relatively low concentration of Nd 3 ions and the short radiative lifetimes (∼100 μs) of the Nd 34 F 3∕2 states, natural broadening and dipole broadening can be considered negligible [6]. So the FWHM of the spectral line can be expressed by [4,5] Δν…”

“…The limited up-level lifetime, the interaction between the dipole field of the adjacent Nd 3 ions, and the thermal phonon vibrations of the crystal lattice are the main causes of homogeneous broadening, producing a Lorentzian line profile [4,5]. In bulk materials with low dopant-active ions, homogeneous broadening of the fluorescence line is attributed mainly to thermal phonons, which include "direct" phonon processes and Raman processes associated with phonon scattering by impurity ions, since, based on the uncertainty principal [6], the radiative lifetimes of the Nd 34 F 3∕2 states are short (typically of the order of 10 −4 s) and the interaction between active ions is weak.…”

Ruby pressure scale in a low-temperature diamond anvil cell

“…The temperature-dependent N-line spectra were also investigated, showing a similar trend for the R lines except for the intensity. [26][27][28][29] While the intensity of the R lines was significantly reduced by a few orders of magnitudes, 29,30 the N lines were found to gain intensity at low temperatures. 26,27 With the Cr 3þ concentration below 0.1% only two R lines from isolated Cr 3þ ions were observed.…”

“…[26][27][28][29] While the intensity of the R lines was significantly reduced by a few orders of magnitudes, 29,30 the N lines were found to gain intensity at low temperatures. 26,27 With the Cr 3þ concentration below 0.1% only two R lines from isolated Cr 3þ ions were observed. The N-line intensity increases with the Cr-doping concentration, although not linearly, reflecting both the increase of the formation probability of paired ions and the energy transfer from single ions to paired ions.…”