Related Experiment Video
Updated: May 31, 2026

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Crossover from incommensurate to commensurate magnetic orderings in CoCr(2)O(4)
1Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu 30013, Taiwan.
Abstract:
The conical spin order of multiferroic CoCr(2)O(4) has been studied by a neutron diffraction to investigate its magnetic phase transitions at temperatures below 40 K. Magnetic order of a spiral spin component with an incommensurate propagation vector of (0.63, 0.63, 0) was observed at 26 K, while at 14.5 K, the incommensurate conical spin order showed a transition into the fixed commensurate propagation vector of (2/3,2/3,0). In addition, two satellite peaks with propagation vectors of (0.035, 0, 0) and (0, 0.035, 0) from the commensurate vector were observed. The widths of these peaks indicate a long-range magnetic order. This new magnetic configuration below 14.5 K may lead to a new model of multiferroic behavior differing from the well-known spin-current model for magnetic ferroelectricity.
Related Concept Videos
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...
2D NMR: Homonuclear Correlation Spectroscopy (COSY)
Spin–Spin Coupling: One-Bond Coupling
Ferromagnetism
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
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...
Hückel's Rule Diagram of π MOs: Frost Circle
A Frost circle is constructed by drawing a polygon whose number of edges is equal to the number of carbons of the given cyclic system, with one of the vertices pointing down. Then, a circle is drawn enclosing the polygon so that...

