Broadening temperature

Russian workers have been active recently in this field. Thus [Eu(thenoyltrifluoro-acetate)3(phen)] has been shown to retain its structure in polystyrene or PVC 298 the second order crystal field parameters ° and have been obtained for a series of complexes [EuL phen)] where L was a series of eight /S-diketonates,299 and the temperature broadening has been investigated, for similar adducts and for EuL2(N03)(Ph3P0)2, of the Stark components of the 1F levels.300... 

Consequently both the temperature broadening and the main part of the shift of the ZPL of the N-V centers at 637 nm ZPL are well described by presented theory supposing that strong softening of the elastic springs in the excited state takes place (see Figs 2a and b). Only relatively small blue shift at T < 40 K most probably has another origin it can be explained by repopulation between strain-induced sublevels of the excited 3E state [32]. 

At same time the low-temperature broadening of resonance line at T < 15 K is reproduced completely in powder case. For single crystal this broadening was related to the short-range magnetic order when temperature is approached to Neel point. 

Figure 4.4. Decay of the surface specular reflection vs thermal disorder, static disorder, and surface annihilation caused by photodimerization. The surface reflection intensity of structure I is plotted vs broadening by temperature (full circles) and by photodimerization (hollow diamonds) which causes static disorder and annihilation of surface anthracene molecules. The solid line is deduced from theoretical calculations (2.126) in the adiabatic approximation. The cloud of hollow diamonds suggest that the density a of unperturbed surface molecules has been reduced below the critical value, with the consequent collapse of the specular reflection cf. (4.20). The inset shows the perfect surface structure (1), the temperature-broadened surface structure (2), and the structure of a photodimerized surface (3), which allowed us to plot the experimental curves.

The combination of both types of profile functions (which is normally due to the predominance of both pressure and temperature broadening) results in a so-called Voigt profile, which can be described by ... 

The gas temperature is determined by the kinetic energy of the neutral atoms and the ions. It can be determined from the Doppler broadening of the spectral lines, as described by Eq. (49). However, to achieve this contributions of Doppler broadening and temperature broadening have to be separated, which involves the use of complicated deconvolution procedures as e.g. shown for the case of glow discharges in Ref. [24]. 

An enhanced dielectric loss maximum was observed at -85°C when a polysulfone sample which contained 0.76 wt. % unassociated water and no detectable level of clustered water (<0.01 wt. %) was run (Fig. 6, curve A). An apparent low temperature broadening of the dielectric loss dispersion was noted for another polysulfone specimen with 0.76 wt. % unassociated water and an additional 0.04 wt. % clustered water (Fig. 6, curve B). However, when a polysulfone sample which contained the same amount of unassociated water as the two prior samples but had 0.16 wt. % clustered water was analyzed, it had a significantly more intense loss peak centered near -105°C (Fig. 6, curve C). We believe that this shift in loss maximum and increase in loss intensity is caused by the development of an additional secondary loss peak about 20° below the 3-transition (Figure 6). In earlier work we had observed the same phenomenon in polycarbonate where the new loss peak occurred about 40 below its 3-transition as a separate loss peak. 

The phenomenon of "temperature-broadening" was also first solved by Williams and Hebb (1951). By using a Gaussian harmonic oscillator, these authors solved the problem of obtaining the shape of absorption (excitation) and emission bands for the quantum mechanical case, namely-... 

Figure 4.9 also shows that an increase in temperature broadens the speed distribution. and shifts the maximum to higher values of c. The area under the two curves in Fig. 4.9 must be the same, since it is equal to unity in both cases. This requires the curve to broaden as the temperature is increased. The speed distribution also depends on the mass of the molecule. At the same temperature a heavy gas has a narrower distribution of speeds than a light gas. 

---