Related Experiment Video
Updated: Sep 23, 2025
09:06
Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.2K
Spin-phonon coupling in ferrimagnet spinel CoMn2O4.
Bommareddy Poojitha1, Aswin Shaji1, Shalini Badola1
1Department of Physics, Indian Institute of Science Education and Research, Bhopal 462066, India.
The Journal of Chemical Physics
|May 14, 2022
Summary
This study explores the mixed-spinel cobalt manganese oxide (CoMn2O4), revealing its distorted tetragonal structure and two ferrimagnetic transitions. Researchers observed spin-phonon coupling, demonstrating its potential for multifunctional devices.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Solid State Chemistry
Background:
- Spinel structures exhibit strong coupling between order parameters, leading to properties like multiferroicity and superconductivity.
- Investigating mixed-spinel compounds like CoMn2O4 is crucial for understanding multifunctional device potential.
Purpose of the Study:
- To investigate the structural, magnetic, and vibrational properties of mixed-spinel CoMn2O4.
- To explore the spin-phonon coupling in this material and its implications.
Main Methods:
- X-ray diffraction (XRD) for structural analysis.
- Magnetization measurements to determine magnetic phase transitions.
- Raman scattering spectroscopy to study vibrational properties and spin-phonon coupling.
Main Results:
- CoMn2O4 was stabilized in a distorted tetragonal structure.
- Two distinct ferrimagnetic phase transitions were observed at 185 K and 90 K.
- Raman scattering revealed phonon renormalization due to spin-phonon coupling, with a measured value of λS² ≈ 2 cm⁻¹.
Conclusions:
- The study confirms the presence of significant spin-phonon coupling in CoMn2O4.
- The observed properties highlight the potential of this mixed-spinel material for developing advanced multifunctional devices.
Related Concept Videos
01:31Ferromagnetism
2.5K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.5K
01:08Spin–Spin Coupling Constant: Overview
1.0K
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
1.0K
01:17Spin–Spin Coupling: One-Bond Coupling
1.1K
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
1.1K
02:42Valence Bond Theory
9.7K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
9.7K
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
1.2K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.2K
01:08NMR Spectroscopy: Spin–Spin Coupling
1.7K
The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved...
1.7K