Freestanding MoS2 nanosheets with different sizes were prepared through a simple exfoliated method by tuning the ultrasonic time in the organic solvent. Magnetic measurement results reveal the clear room-temperature ferromagnetism for all the MoS2 nanosheets, in contrast to the pristine MoS2 in its bulk form which shows diamagnetism only. Furthermore, results indicate that the saturation magnetizations of the nanosheets increase as the size decreases. Combining the X-ray photoelectron spectroscopy, transmission electron microscopy, and electron spin resonance results, it is suggested that the observed magnetization is related to the presence of edge spins on the edges of the nanosheets. These MoS2 nanosheets may find applications in nanodevices and spintronics by controlling the edge structures.

Spin-polarized density functional theory has been used to study the properties of seven kinds of divacancies in graphitic boron nitride sheets. We find that some divacancies are magnetic and the symmetry of the sheets is broken by the distortion of atoms which are close to the vacancies. According to the formation energies, the neighboring boron and nitrogen vacancy pair is the most likely to form. Our calculations demonstrate that the divacancies can induce fundamental changes in the electronic properties of the sheet, making semiconducting–to–half-metallic transitions occur. The results can be used to customize the spintronics devices.

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In this study, rotational magnetization curves are used to investigate the anisotropy and the rotational magnetization process of uniaxial magnets. We measured the projection of magnetization as a function of angle between the magnetic field and the reference axis. The information about anisotropy, such as the directions of the easy axis and hard axis, as well as the anisotropy field Hk(i), is acquired. Simultaneously, the rotational magnetization reversal processes are derived. The Co and Fe28Co61Zr11 magnetic thin films with induced in-plane uniaxial anisotropy have been researched. We found that the rotational magnetization reversal process of the Co film is a coherent rotation. However, the Fe28Co61Zr11 film shows the similar behavior, except for a noncoherent rotation appearing when a small field parallels the hard axis.

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