Broadband Terahertz Time-Domain Spectroscopy of Archaeological Baltic Amber

Abstract

Abstract. We performed the broadband terahertz time-domain spectroscopy on archaeological Baltic amber at 40 million years old. We determined the real and imaginary parts of the complex dielectric constants in the frequency range from 0.2 to 6.5 THz. The imaginary part of the complex dielectric constants showed a broad peak at 1.51 THz and a small peak at 4.0 THz. A boson peak, which is the characteristic low energy excitation of a glassy state, was not observed above 0.2 THz even in low temperatures.

Non-destructive comparative evaluation of fossil amber using terahertz time-domain spectroscopy

“…In addition, the spectral data of Sasaki et. al [ 28 ] is shown. The Baltic amber spectral data from the present work qualitatively agrees very well with the previous results of Sasaki over the datasets common spectral range.…”

“…(e) Wyoming and Baltic amber: WY01_A (black lines) and BA-A (dark gray lines) amber samples. The spectral data of Sasaki et al Baltic data [ 28 ] are shown in light gray.…”

“…As a starting point, Fig 1 shows a fit of Sasaki et. al’s [ 28 ] spectral data for Baltic Amber to the Debye Model, Cole-Cole, and Cole-Davidson models. While all three models yield good fits to the real permittivity data, note that the imaginary permittivity data is better fit by both the Cole-Cole and Cole-Davidson models compared to the Debye model indicating that the Baltic Amber is better described by a distribution of dielectric relaxation times.…”

“…There are few publications related to characterization of amber in the terahertz spectral range. One research paper [ 28 ], centers around characterizing a single deposit of Baltic amber. In that work, the spectral transmission through amber is measured from 0.14–6.5 THz.…”

Synthesis, Spectral Correlations and Antimicrobial Activities of 2-Pyrimidine Schiff’s Bases

“…intra-molecular as well as inter-molecular [6]. Schiff's bases are widely studied and used in the fields of organic synthesis and metal ion complexation [7] for a number of reasons: their physiological and pharmacological activities [8] their use in ionselective electrodes [9] in the determination of heavy metals ions in environmental samples [10] and in the extraction of metals ions [11,12] and their many catalytic applications (e.g. for epoxidation of olefins, alkene cyclopropanation [13,14] trimethylsilylcyanation of ketones [15] asymmetric oxidation of methyl phenyl sulfide enantioselective epoxidation of silylenol [16] and ring-opening polymerization of lactide [17].…”