Intercrystalline magnetic interaction and hysteresis characteristics of high-coercivity cobalt-based alloy coatings

δM(H) curves and the time dependences of the magnetization and the rotational hysteresis losses are used to analyze the effect of intercrystalline magnetic interaction on the magnetization reversal and the hysteresis characteristics of nanostructured cobalt-based alloy coatings, which manifest themselves in a change in the relations between the rotation and displacement of reversible and irreversible processes and between thermally activated and field processes.     

AlScN films prepared by alloy targets and SAW device characteristics

In this paper,we reported a surface acoustic wave(SAW) device prepared and optimized by piezoelectric films containing AIN,AIScN(Sc-20 at%) and AIScN(Sc-30 at%) by reactive magnetron sputtering using Al and AISc alloy targets.We calculated the material intrinsic electromechanical coupling coefficient k_t² of AlScN(Sc-20 at%) and AlScN(Sc-30 at%) which are much better than AIN.It can be explained by the lattice softening.Furtherly,the results were confirmed by transmission el...     

Effect of zirconium content on exchange coupling and magnetization reversal of nanocrystalline Nd_(12.3)Fe_(81.7-x)Zr_xB_6 alloy

The effect of Zr content on exchange coupling and magnetization reversal of the Nd12.3Fe81.7-xZrxB6(x=0-3.0) ribbons was systematically investigated.Interaction domains were imaged by magnetic force microscopy(MFM).The strength of interactions determined byWohlfarth's analysis increased first with Zr content x increasing,reached the maximum value at x=1.5,and then decreased with x further increasing.Initial magnetization curves and dependence of coercivity and remanence on applied magnetic field showed that...     

Effect of heterogeneous microstructure on magnetization reversal mechanism of hot-deformed Nd-Fe-B magnets

The hot-deformed(HD) Nd-Fe-B magnets show heterogeneous microstructure composed of coarse and fine grain regions. It is significant to fully understand the influence of this complex microstructure on the magnetization reversal process which can give the guidance for the enhancement of the magnetic properties. In this paper, the heterogeneous microstructure of the(HD) Nd-Fe-B magnets were characterized from the morphology, size, macro-texture and micro-structure. In addition, the magnetization reversal process of the HD Nd-Fe-B magnets was systematically analyzed by magnetic measurement, insitu domain evolution observation and micromagnetic simulation. The results indicate that the HD NdFe-B magnets mainly consist of fine grain regions(FGRs) and coarse grain regions(CGRs). The FGRs show plate-like grains with fine grain size and strong c-axis texture, while the CGRs show equiaxial grains with large grain size and weak c-axis texture. In particular, it is worth noting that the texture in homogeneity exists not only between FGRs and CGRs, but also inside both the FGRs and CGRs. The dominant coercivity mechanism of the HD Nd-Fe-B magnets is domain wall pinning. Also, the experimental analysis shows that the reverse domain is formed and expanded in the CGRs at low reverse applied field, while the reverse domain occurs in the FGRs at higher reverse applied field. The micromagnetic simulation results also confirm the above magnetization reversal process. In addition, micromagnetic simulation results also show that the orientation of the grains also affects the pinning strength, besides the grain size.     

Determination of matrix dependences between the magnetic and elastoplastic characteristics of steels during tension

Stress-strain and coercive force-strain diagrams are experimentally obtained for grade 45 and St3 steels. These diagrams are used to construct matrix dependences between the elastoplastic and magnetic properties of the steels in order to determine the level of stresses in construction members made of these steels.     

Structural characteristics, magnetic nonuniformity, and magnetic intercrystalline interaction in high-coercivity Co-W and Co-P coatings

The crystal structure and magnetic properties of Co-W (4–6 at % W) and Co-P (2–5 at % P) coatings produced by electrodeposition at various temperatures (Co-W coatings) or sodium hypophosphite concentrations in an electrolyte (Co-P coatings) are studied. The coatings consist of crystallites having an hcp structure with a [001] and/or a [100] texture depending on the deposition conditions. The structural characteristics, the magnetic nonuniformity, and the magnetic intercrystalline interaction are found to correlate with each other.