Related Experiment Video
Updated: Jul 28, 2025

Synthesis and Microdiffraction at Extreme Pressures and Temperatures
Published on: October 7, 2013
High-Pressure-Stabilized Post-Spinel Phase of CdFe2O4 with Distinct Magnetism from Its Ambient-Pressure Spinel Phase
Beihong Li1,2, Xubin Ye2, Xiao Wang2
1Department of Physics, Shanghai Normal University, Shanghai 200234, China.
Abstract:
α-CdFe2O4 stabilizes its normal spinel structure due to the covalent Cd-O bond, in which all the connections between adjacent FeO6 octahedral are edge-shared, forming a typical geometrically frustrated Fe3+ magnetic lattice. As the high-pressure methods were utilized, the post-spinel phase β-CdFe2O4 with a CaFe2O4-type structure was synthesized at 8 GPa and 1373 K. The new polymorph has an orthorhombic structure with the space group Pnma and an 11.5% higher density than that of its normal spinel polymorph (α-CdFe2O4) synthesized at ambient conditions. The edge-shared FeO6 octahedra form zigzag S = 5/2 spin ladders along the b-axis dominating its low-dimensional magnetic properties at high temperatures and a long-range antiferromagnetic ordering with a high Néel temperature of TN1 = 350 K. Further, the rearrangement of magnetic ordering was found to occur around TN2 = 265 K, below which the competition of two phases or several couplings induce complex antiferromagnetic behaviors.
More Related Videos
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Related Concept Videos
Colors 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...
Valence Bond Theory
Ferromagnetism
Crystal 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...
Diamagnetism
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....
Crystal Field Theory - Tetrahedral and Square Planar 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,...