Related Experiment Video
Updated: Aug 16, 2026

Exploring the Radical Nature of a Carbon Surface by Electron Paramagnetic Resonance and a Calibrated Gas Flow
Published on: April 24, 2014
Electron spin resonance (ESR) studies of CO2- radicals in irradiated A and B-type carbonate-containing apatites
Abstract:
ESR spectra of irradiated carbonate-containing hydroxyapatites are complex and strongly dependent on the method of preparation of these materials. This paper describes results of our studies of the ESR spectra of irradiated A- and B-type carbonated hydroxyapatites. The most intense and stable lines in these spectra are attributed to CO2- radicals. The ESR spectrum of A-type carbonated apatite can be predominantly due to either axial or orthorhombic CO2- species, depending on whether the apatite was cooled in or without a CO2 flow. The B-type carbonated apatite has an ESR spectrum composed basically of signals from isotropic and orthorhombic CO2- species. These signals are different in intensity, line width, and g-factor for samples heated for 3 h at 200, 400 and 600 degrees C. The effect of the method of preparation of the A- and B-type carbonated apatites on the ESR spectra and the application of these materials to the ESR dating and dosimetry are discussed.
Related Concept Videos
Radicals: Electronic Structure and Geometry
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals
Raman Spectroscopy: Overview
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
Atomic Emission Spectroscopy: Overview
Atomic Emission Spectroscopy: Lab
Double Resonance Techniques: Overview
Spin decoupling is usually achieved by...

