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Voltage control magnetism has been widely studied due to its potential applications in the next generation of information technology. PMN-PT, as a single crystal ferroelectric substrate, has been widely used in the study of voltage control magnetism because of its excellent piezoelectric properties. However, most of the research based on PMN-PT only studies the influence of a single tensile (or compressive) stress on the magnetic properties due to the asymmetry of strain. In this work, we show the effect of different strains on the magnetic anisotropy of an Fe19Ni81/(011) PMN-PT heterojunction. More importantly, the (011) cut PMN-PT generates non-volatile strain, which provides an advantage when investigating the voltage manipulation of RF/microwave magnetic devices. As a result, a ferromagnetic resonance field tunability of 70 Oe is induced in our sample by the non-volatile strain. Our results provide new possibilities for novel voltage adjustable RF/microwave magnetic devices and spintronic devices.

The original formula to calculate the tunneling rate through event horizons is apparently dependent on the type of coordinates used. In this paper, we propose an invariant expression under canonical transformations to study the tunneling effect. Moreover, the problem of factor 2 is solved naturally. As an application of this expression, we obtain the same tunneling rate both in the Schwarzschild and the Painleve coordinates. It is shown that once the suitable formula to calculate tunneling rate is correctly identified, the tunneling method is manifestly covariant.

Studies of bulk MgCu2-type rare-earth iron compounds with Laves phase are reviewed. The relationship between magnetostriction and structural distortion and the consequent crystallographic method for measuring magnetostriction are introduced at first. Then we review recent progress in understanding bulk magnetostrictive Laves phase materials, especially the magnetostriction and the minimization of the anisotropy of the light rare-earth Pr- and Sm-based compounds. Finally, a summary and outlook for this kind of compounds are presented.

The mass, electric charge, and temperature of black holes in the Reissner—Nordstrom—de Sitter quintessence (RN—dSQ) spacetime are obtained. The heat capacities of the RN—dSQ black holes for certain electric charges and masses are analyzed. The electrostatic energy and dark energy in the RN—dSQ black holes are also calculated.