Related Experiment Video
Updated: Dec 25, 2025
08:25
Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene
Published on: July 3, 2015
11.9K
Negative magnetization, complex magnetic ordering and applications of Cr-doped Co2TiO4
Q S Fu1, X H Chen1, C Chakrabarti1
1School of Physics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China. yuansl@hust.edu.cn.
Physical Chemistry Chemical Physics : PCCP
|March 21, 2020
Summary
Negative magnetization was observed in Co2Ti1-xCrxO4 inverse spinel ceramics up to x=0.2. The x=0.1 sample shows potential for magnetic switching and constant temperature applications due to unique magnetic properties.
Area of Science:
- Materials Science
- Solid State Physics
- Magnetism
Background:
- Inverse spinel ferrimagnetic materials exhibit complex magnetic behaviors.
- Tuning magnetic properties through elemental substitution is crucial for advanced applications.
Purpose of the Study:
- Synthesize Polycrystalline Co2Ti1-xCrxO4 (0 ≤ x ≤ 0.2) inverse spinel ceramics.
- Investigate the effect of Cr substitution on magnetic properties, including negative magnetization and compensation temperature.
- Explore potential applications based on observed magnetic effects.
Main Methods:
- Sol-gel synthesis technique for ceramic preparation.
- DC magnetization measurements in field-cooled mode.
- Ferrimagnetic Curie-Weiss fitting and mean-field theory for exchange constant calculation.
Main Results:
- Negative magnetization observed for Cr content up to x = 0.2.
- Inter sublattice magnetic interaction strength shows a non-monotonic trend with Cr content, minimizing at x = 0.1.
- The x = 0.1 sample exhibits the highest compensation temperature.
- Stable magnetic switching effect and coexistence of normal/inverse magnetocaloric effects identified.
Conclusions:
- Cr substitution in Co2Ti1-xCrxO4 influences magnetic interactions and compensation temperature.
- The x = 0.1 sample demonstrates potential for magnetic switching, data storage, and constant temperature applications at 54 K.
More Related Videos
Related Concept Videos
03:02Colors and Magnetism
13.6K
Color in Coordination Complexes
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...
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...
13.6K
02:58Crystal Field Theory - Octahedral Complexes
30.1K
Crystal Field Theory
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...
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...
30.1K
02:42Valence Bond Theory
10.9K
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...
10.9K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
47.5K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
47.5K
01:31Ferromagnetism
2.9K
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...
2.9K
01:26Diamagnetism
2.9K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.9K