Related Experiment Video
Updated: May 22, 2025

Tuning Oxide Properties by Oxygen Vacancy Control During Growth and Annealing
Published on: June 9, 2023
Oxygen Vacancy-Induced Room-Temperature Ferromagnetism in a Layered Aluminosilicate Material
Hongyun Ji1, Jian Peng1, Meijun Yang1
1State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
Abstract:
Defect engineering has been utilized to induce ferromagnetism in various nonmagnetic van der Waals (vdW) crystals, which are vital for fundamental research and applications. Herein, oxygen vacancies were successfully created in montmorillonite, a layered aluminosilicate, by acetic acid treatment and annealing in an argon atmosphere. This treatment facilitated the transition from paramagnetism to room-temperature ferromagnetism with a Curie temperature of 330 K. As the annealing temperature increased, in-plane stretching along the [002] crystallographic direction was found to reduce the formation energy of oxygen defects, thereby promoting the creation of oxygen vacancies. By controlling the concentration of oxygen vacancies, precise regulation of the material's ferromagnetic properties was achieved. This work presents a novel room-temperature ferromagnetic material and advances the study of oxygen vacancy-induced ferromagnetism in vdW materials.
Related Concept Videos
Ferromagnetism
Trends in Lattice Energy: Ion Size and Charge
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...
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....
Valence Bond Theory
Alkali Metals
Table 1: Properties of the alkali metals

