Related Experiment Video
Updated: Feb 5, 2026
05:57
Blood Flow Imaging with Ultrafast Doppler
Published on: October 14, 2020
8.5K
Ultrafast proton/deuteron dynamics in KTaO
Atsunori Sakurai1, Koji Ando2, Satoshi Ashihara1
1Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan.
The Journal of Chemical Physics
|September 17, 2018
Summary
Researchers observed new signals in infrared spectroscopy of KTaO3, revealing insights into proton conduction. This study enhances understanding of how protons move within solid oxides.
Area of Science:
- Solid-state physics
- Materials science
- Spectroscopy
Background:
- Proton conduction in oxides is crucial for energy applications.
- Understanding the interaction between protons and lattice vibrations is key.
- Potassium tantalate (KTaO3) is a model system for studying these phenomena.
Purpose of the Study:
- To investigate the OD stretching mode in KTaO3 using infrared pump-probe spectroscopy.
- To elucidate the mechanism of proton/deuteron conduction in solid oxides.
- To determine the role of lattice vibrations in proton dynamics.
Main Methods:
- Infrared pump-probe spectroscopy was employed to measure the OD stretching mode.
- Temperature-dependent absorption spectra of OH/OD were analyzed.
- Potential energy surfaces for proton/deuteron motion were calculated.
Main Results:
- Induced absorption (1-2 transition) and bleaching (0-1 transition) signals of the OD stretching mode were observed for the first time in oxide crystals.
- Both signals exhibited a long decay time of approximately 200 ps.
- Potential anharmonicity was determined to be 3.6%, and an O-Ta-O bending phonon mode was identified as responsible for potential fluctuations.
Conclusions:
- The study provides novel insights into proton/deuteron dynamics in KTaO3.
- The findings contribute to understanding proton conduction mechanisms in solid oxides.
- The identified phonon mode offers a target for future material design.
Related Concept Videos
01:07Proton (¹H) NMR: Chemical Shift
3.5K
Organic molecules primarily contain carbon and hydrogen atoms. While all the hydrogen isotopes are NMR-active, protium or hydrogen-1 is the most abundant. It has a significant energy separation between its nuclear spin states due to its large gyromagnetic ratio. As per Boltzmann's distribution, an increase in the energy separation implies a greater excess population of nuclei available for excitation, resulting in a strong NMR absorption signal.
Absorption signals of all the protium nuclei...
Absorption signals of all the protium nuclei...
3.5K
02:20Dynamic Equilibrium
62.7K
A reversible chemical reaction represents a chemical process that proceeds in both forward (left to right) and reverse (right to left) directions. When the rates of the forward and reverse reactions are equal, the concentrations of the reactant and product species remain constant over time and the system is at equilibrium. A special double arrow is used to emphasize the reversible nature of the reaction. The relative concentrations of reactants and products in equilibrium systems vary greatly;...
62.7K
01:10¹H NMR of Labile Protons: Temporal Resolution
1.7K
Protons bonded to heteroatoms such as nitrogen and oxygen exhibit a range of chemical shift values. This is due to the varying degree of hydrogen bonding between the proton and the heteroatom in other molecules. The extent of hydrogen bonding affects the electron density around the proton, thereby giving different chemical shift values for the protons in the proton NMR spectrum.
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
1.7K
00:48¹H NMR of Labile Protons: Deuterium (²H) Substitution
1.3K
This lesson illustrates the role of deuterium substitution in simplifying the NMR spectrum of compounds comprising labile protons. One method employed is the use of deuterium. Amongst the three isotopes of hydrogen, deuterium (2H) has a nucleus composed of one proton and one neutron. When the D2O solvent is added to a pure dry ethanol solution, its labile proton is substituted with deuterium.
1.3K
01:03¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons
4.2K
Protons in identical electronic environments within a molecule are chemically equivalent and have the same chemical shift. The replacement test is a useful tool to identify chemical equivalence and predict NMR spectra. A substituent replaces each of the protons being examined and the resulting molecules are compared. If the same molecule is obtained, the protons are equivalent or homotopic. Replacement of any hydrogens in ethane by chlorine yields chloroethane because all six protons are...
4.2K
00:58¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons
3.3K
Replacing each alpha-hydrogen in chloroethane by bromine (or a different functional group) yields a pair of enantiomers. Such protons are called prochiral or enantiotopic and are related by a mirror plane. Enantiotopic protons are chemically equivalent in an achiral environment. Because most proton NMR spectra are recorded using achiral solvents, enantiotopic hydrogens yield a single signal.
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
3.3K