The success of composite thin films of rare earth permanent magnet
World Executive Technology channel (tech.icxo.com) message: the development of
rare-earth permanent magnetic materials to the third generation, people are
still hard to explore more excellent intrinsic magnetic properties of new
magnetic compounds. Iron-based
rare-earth nitrides became one of the hot people. Zhang Zhidong research team led by researchers at the magnetic rare-earth
transition metal compounds, phase transitions, metastable rare earth opposite
the steady-state phase transition mechanism, the magnetic properties of
nanocomposite magnetic coupling mechanism, quantum effects and magnetic
interactions between the association has made system, in-depth research. The results heighten the perception of the structural phase transition in
magnetic materials, magnetic phase transitions, such as nano-composite magnetic
coupling and understanding of the phenomenon.
Group by looking for rare-earth metastable phase formation of a common law
analysis of rare earth and between the metastable phase transition to a stable
compound and found that structural symmetry is the key factor; nanocomposite
rare earth permanent magnetic materials for magnetic coupling mechanism to carry
out experimental and theoretical research; combination of hard and soft magnetic
phases in nano-scale phase of both internal and intrinsic magnetic
contributions, proposed the concept of effective exchange coupling constant; and
so on. Task Force members in recent years published in international journals related
to more than 100 papers, invited to international journals and manuals written
for rare-earth transition metal compounds, rare-earth metastable phase, thin
films and spin waves in superlattices, double quantum wells in the quantum
interference effect, nano-composite magnetic materials such as special synthesis
report 6.
Recently, research work in the early system on the basis of Zhang Zhidong
research team with University of Nebraska Lincoln cooperation, but also in the
preparation of high-performance multi-layer thin-film nanocomposite rare earth
permanent magnet progress. Since the experiments found on the intergranular magnetic exchange coupling, the
theoretical predictions obtained nanocomposite permanent materials with high
remanence and high maximum energy product. However, to date bulk nanocomposite permanent magnetic materials, the maximum
energy product of the experimental value is much lower than the theoretical
expected value. To address this issue, they have developed in the design of nanoscale materials,
rare earth permanent magnet technology, prepared by magnetron sputtering
multilayer thin film nanocomposite rare earth permanent magnet, by controlling
the thickness of the multilayer film to control the annealing process of hard
magnetic phase and soft phase grain growth and distribution. The use of high-resolution transmission electron microscopy cross-section sample
plane and characterization, that the hard magnetic phase and soft phase
distribution. Well-designed multi-layer film of 40 nm from the grain size of hard magnetic
phase and the continuous distribution of soft magnetic phase. Resulting in multi-layer film to achieve a remanent magnetic
exchange coupling and enhancement, the effective combination of hard and soft
magnetic phase with good magnetic properties, to achieve a remanence enhancement
effect in thin-film magnet to get the maximum energy product 203 kJ / m3.
The experts spoke highly of the results, saying that "in the international field
of study at the advanced level, to explore new permanent magnetic materials
provides a new idea, the development of permanent magnetic materials and
application of important guiding significance."