Hyperquenched glassy films of water. A study by hole burning
- Iowa State Univ., Ames, IA (United States)
The results of infrared absorption (-OH) experiments and nonphotochemical hole-burning experiments of aluminum-phthalocyanine-tetrasulfonate (ATP) in hyperquenched glassy films of water (HGW) are reported. Zero-phonon hole widths were usually determined for a burning and reading temperature of 5 K. Hole growth kinetics were always monitored at a burning temperature of 5 K. It was found, for example, that HGW annealed or deposited at 140 K yields a zero-phonon hole width of 180 MHz, a factor of 3 times narrower than the hole of HGW formed at T{sub D} = 5 K. Decrease of the hole width with annealing onsets at T{sub A} nearly equals 90 K. Both unannealed and annealed films yielded a T{sup 1.3} power law for the dependence of the hole width on the burning temperature ({<=}10 K), proving that pure dephasing/spectral diffusion is governed by the electron-TLS{sub int} (intrinsic two-level systems) interaction. An interpretation of the aforementioned configuration relaxation, onsetting at nearly 90 K, in terms of the TLS{sub int} model is given. ATP in HGW turns out to be the most efficient system for nonphotochemical hole burning yet discovered, with an average quantum yield as high as 0.18. (The S{sub 1} lifetime of ATP is 4.8 ns.) Remarkably, the hole burning is essentially inoperative in cubic ice formed by warming of HGW. However, this cessation is consistent with the current mechanism for nonphotochemical hole burning. 62 refs., 10 figs., 2 tabs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 50777
- Journal Information:
- Journal of Physical Chemistry, Vol. 99, Issue 19; Other Information: PBD: 11 May 1995
- Country of Publication:
- United States
- Language:
- English
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