Related Experiment Video
Updated: Jun 6, 2026
Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
75As NQR characterisation of cobaltite (CoAsS)
T C L Ly1, A Curtain1, M Crowther1
1CSIRO, Mineral Resources, Australia.
None:
This paper describes the first known detection of cobaltite (CoAsS) by 75As NQR spectroscopy. The 75As resonance was observed from a natural cobaltite sample with a peak signal at 87 MHz with a FWHM of 1.11 MHz. The T1 and T2 relaxation times were measured and found to be 29.4 ms and 343 μs respectively. This observation was aided by simulations of the unit cell using the density functional theory (DFT) program, WIEN2k [1] that simulated the peak resonance within 5%. The detection of cobaltite was motivated by the expansion on the suite of minerals that are amenable to quantification in mining applications using magnetic resonance based on-line monitoring systems.
Related Concept Videos
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
02:42Valence Bond Theory
02:34Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:42Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
02:54Coordination Compounds and Nomenclature