We have made a survey of ceramics for the inner parts of the transmission-type pressure cell to achieve the high pressure and the high transmission in the THz range. By using the optimal combination of ZrO2-based ceramic and Al2O3 ceramic, we have succeeded in obtaining a pressure up to 1.5 GPa and a frequency region up to 700 GHz simultaneously. We show the high-pressure ESR results of the Shastry-Sutherland compound SrCu2(BO3)2 as an application. We observed the direct ESR transition modes between the singlet ground state and the triplet excited states up to a pressure of 1.51 GPa successfully, and obtained the precise pressure dependence of the gap energy. The gap energy is directly proved to be suppressed by the pressure. Moreover, we found that the system approaches the quantum critical point with pressure by comparing the obtained data with the theory. This result also shows the usefulness of high-pressure ESR measurement in the THz region to study quantum spin systems.
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http://dx.doi.org/10.1021/acs.jpcb.5b03664 | DOI Listing |
Biosensors (Basel)
December 2024
School of Integrated Circuits, Shandong University, Jinan 250100, China.
Terahertz (THz) spectroscopy, an advanced label-free sensing method, offers significant potential for biomolecular detection and quantitative analysis in biological samples. Although broadband fingerprint enhancement compensates for limitations in detection capability and sensitivity, the complex optical path design in operation restricts its broader adoption. This paper proposes a multi-degree-of-freedom stretchable metasurface that supports magnetic dipole resonance to enhance the broadband THz fingerprint detection of trace analytes.
View Article and Find Full Text PDFSmall
December 2024
School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, 230026, China.
Hydrogels present significant potential in flexible materials designed for electromagnetic interference (EMI) shielding, attributed to their soft, stretchable mechanical properties and water-rich porous structures. Unfortunately, EMI shielding hydrogels commonly suffer from low mechanical properties, deficient fracture energy, and low strength, which limit the serviceability of these materials in complex mechanical environments. In this study, the double network strategy is successfully utilized along with the Hofmeister effect to create MXene/PAA (polyacrylic acid)-CS (chitosan) hydrogels and further strengthen and toughen the gel with (NH)SO solution.
View Article and Find Full Text PDFJ Chem Phys
December 2024
Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05513-970 São Paulo, SP, Brazil.
Molecular dynamics (MD) simulation is used to study the intermolecular dynamics in the THz frequency range of the ionic liquid 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, [C2C1im][FSI]. Non-polarizable and polarizable models for classical MD simulation are compared using as quality criteria ab initio molecular dynamics (AIMD) and experimental data from far-infrared (FIR) spectroscopy and previously published data of inelastic x-ray scattering (IXS). According to data from IXS spectroscopy, incorporating polarization in the classical MD simulation has relatively little effect on the dispersion curve (excitation frequency vs wavevector) for longitudinal acoustic modes.
View Article and Find Full Text PDFACS Omega
December 2024
School of Psychology, University of Wollongong, Wollongong, New South Wales 2522, Australia.
The biological effects of electromagnetic field (EMF) irradiation in the terahertz (THz) range remain ambiguous, despite numerous studies that have been conducted. In this paper, the metabolic response of K 12 to EMF irradiation was examined using a 1.0 W m incident synchrotron source (SS) in the range of 0.
View Article and Find Full Text PDFJ Chem Phys
December 2024
Department of Chemistry, University of Graz, Heinrichstraße 28/IV, 8010 Graz, Austria.
Intermolecular vibrations are extremely challenging to describe but are the most crucial part for determining entropy and hence free energies and enable, for instance, the distinction between different crystal-packing arrangements of the same molecule via THz spectroscopy. Herein, we introduce a benchmark dataset-V30-containing 30 small molecular dimers with intermolecular interactions ranging from exclusively van der Waals dispersion to systems with hydrogen bonds. All the calculations are performed with the gold standard of quantum chemistry CCSD(T).
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