The researchers from the Ningbo Institute of Materials Technology and Engineering (NIMTE), the Chinese Academy of Sciences (CAS) recently developed a new technique to improve the coercive force of the magnets.

In their research, the ions bombardment was employed to act on magnets, and the coercive force can be elevated obviously by controlling the energy and dose of ion bombardment (Fig.1).The ion bombardment is a non-equilibrium process, and the formation of new materials and structures is not restricted by the classical thermodynamics and dynamics. This technique can be used in surface modification for any materials. It is an effective means to develop the ideal new properties of materials

It is first proposed that the nonlinear lattice excitation created by ion bombardment plays a crucial role to improve the coercive force (Fig.2). The intrinsical relation is revealed between ion bombardment, microstructure and coercive force. In their study, the effect and mechanism of the induced factors created by ion bombardment, especially nonlinear lattice excitation on the coercive force of the magnet, were discussed.

More details of this work can be found in their recent published paper in Materials Letter 98（2013）102-104 and the related patent has been filed (201210007966.9).

Fig.1 Magnetic hysteresis curves for NdFeB magnet treated by argon ion bombardment with
different energies

Nonlinear lattice excitation

Fig. 2 Nonlinear lattice excitation created by ion bombardment plays a crucial role to
improve the coercive force

Prof.Jinlong Li   lijl@nimte.ac.cn

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