Physics

Magnetic semiconductor

Nanotechnology

Organic chemistry

Magnetization

Ferromagnetism

Magnetic field

Semiconductor

van der Waals force

Magnetometer

Composite material

Spintronics

Magnetic force microscope

Chemistry

Materials science

Magnetism

Condensed matter physics

Molecule

Ferrite (magnet)

Quantum mechanics

Optoelectronics

Curie temperature

Nature Communications

The discovery of magnetism in ultrathin crystals opens up opportunities to explore new physics and to develop next-generation spintronic devices. Nevertheless, two-dimensional magnetic semiconductors with Curie temperatures higher than room temperature have rarely been reported. Ferrites with strongly correlated d-orbital electrons may be alternative candidates offering two-dimensional high-temperature magnetic ordering. This prospect is, however, hindered by their inherent three-dimensional bonded nature. Here, we develop a confined-van der Waals epitaxial approach to synthesizing air-stable semiconducting cobalt ferrite nanosheets with thickness down to one unit cell using a facile chemical vapor deposition process. The hard magnetic behavior and magnetic domain evolution are demonstrated by means of vibrating sample magnetometry, magnetic force microscopy and magneto-optical Kerr effect measurements, which shows high Curie temperature above 390 K and strong dimensionality effect. The addition of room-temperature magnetic semiconductors to two-dimensional material family provides possibilities for numerous novel applications in computing, sensing and information storage.

Ultrathin ferrite nanosheets for room-temperature two-dimensional magnetic semiconductors