Piezoelectric changes of anisotropy and magnetization in ferrite-garnet film
The results of the effect of mechanical strain on magnetic anisotropy, the direction of magnetization vector and domain structure of ferrite-garnet film, rigidly connected with the zirconium-titanium lead (PZT) piezoceramic plate are presented. Since such a sandwich structure could be remagnetized both by magnetic field and electric voltage it could be used as the electro-magnetooptical modulator of light or spin switching cell in spintronics.
Ferrite-piezoelectric light modulator with electric and magnetic control of magnetization
The influence of mechanical stresses developed in a piezoelectric lead zirconate titanate (PZT) plate on the domain structure of mechanically coupled epitaxial yttrium iron garnet (YIG) film has been studied. The application of electric voltage to the piezoelectric plate leads to magnetoelastic variations in the anisotropy of the garnet film, which is manifested by reorientation of the magnetization vector from the direction perpendicular to the film plane to a direction parallel to this plane. Using this effect, it is possible to perform magneto-optical modulation of light transmitted through the film. Estimations of the influence of film parameters on the orientation of magnetization and characteristics of light beam allow the optimum parameters of the composite structure for various modulation regimes to be determined.
Experimental investigation of the geotechnical properties and microstructure of lime-stabilized saline soils under freeze-thaw cycling
Abstract The Song-Nen Plain in northeastern China holds one of the three largest expanses of soda saline-alkali soil in the world. Due to its disadvantageous geotechnical properties, the saline soil in this area is unable to meet the needs of construction projects. This study evaluates the stabilizing effect of adding lime to such soils. Specifically, it investigates how the physicochemical and mechanical properties and microstructure of soda saline-alkali soil are altered by lime and how these changes are affected by both freeze-thaw cycling and the duration of curing. The results reveal that adding lime to saline soil transforms clay particles into sand and silt particles and causes the pore size distribution (PSD) to become bimodal, with small-pore and macropore populations. An increase in lime content leads to an increase in the unconfined compressive strength (UCS) but a gradual decrease in both the cation exchange capacity (CEC) and plastic index. Freeze-thaw cycles break up coarse particles and aggregate finer particles, increasing the diameter of macropores and decreasing the USC; however, the effect on specimens with >9% lime is negligible. It is further shown that the geotechnical properties of the soil change immediately after the addition of lime, indicating that the cation exchange reaction takes place very quickly. Furthermore, the pozzolanic reaction leads to an increase in the percentage of sand-sized particles and a decrease in porosity after 28 days of curing. Overall, these results indicate that it is feasible to use lime to improve the engineering properties of soda saline-alkali soil in this area.