Related Experiment Video
Updated: May 18, 2026

Radio Frequency Magnetron Sputtering of GdBa2Cu3O7−δ/ La0.67Sr0.33MnO3 Quasi-bilayer Films on SrTiO3 (STO) Single-crystal Substrates
Published on: April 12, 2019
Magnetically-induced lattice distortions and ferroelectricity in magnetoelectric GdMnO3
J Agostinho Moreira1, A Almeida, M R Chaves
1IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, Porto, Portugal. jamoreir@fc.up.pt
Abstract:
In this work we investigate the magnetic field dependence of A(g) octahedra rotation (tilt) and B(2g) symmetric stretching modes frequencies at different temperatures. Our field-dependent Raman investigation at 10 K is interpreted by an ionic displacive nature of the magnetically-induced ferroelectric phase transition. The increasing frequency of the A(g) tilt mode with magnetic field gives evidence for the increase of the MnO(6) tilt angle, which in turn leads to a weakening of the ferromagnetic exchange interaction, yielding the necessary conditions for the onset of ferroelectricity on the basis of the inverse Dzyaloshinskii-Moriya interaction. The frequency change of the B(2g) symmetric stretching mode at the ferroelectric phase transition enables one to estimate the shift of oxygen ion positions and the corresponding spontaneous polarization of 480 μC m(-2) in magnitude, which is of the same order as earlier reported values in single crystals.
Related Concept Videos
Ferromagnetism
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.
Paramagnetism
Potential Due to a Magnetized Object
The vector...
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 eye.
Valence Bond Theory
