Topological insulators (TIs) have emerged as some of the most efficient spin-to-charge convertors because of their correlated spin-momentum locking at helical Dirac surface states. While endeavors have been made to pursue large "charge-to-spin" conversions in novel TI materials using spin-torque-transfer geometries, the reciprocal process "spinto-charge" conversion, characterized by the inverse Edelstein effect length (λ IEE ) in the prototypical TI material (Bi 2 Se 3 ), remains moderate. Here, we demonstrate that, by incorporating a "second" spin-splitting band, namely, a Rashba interface formed by inserting a bismuth interlayer between the ferromagnet and the Bi 2 Se 3 (i.e., ferromagnet/Bi/Bi 2 Se 3 heterostructure), λ IEE shows a pronounced increase (up to 280 pm) compared with that in pure TIs. We found that λ IEE alters as a function of bismuth interlayer thickness, suggesting a new degree of freedom to manipulate λ IEE by engineering the interplay of Rashba and Dirac surface states. Our finding launches a new route for designing TI-and Rashba-type quantum materials for next-generation spintronic applications.

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The current research examines the impact of Ca2+ substitution on the phase and electrical properties of (Ba1−xCax)Ti4O9, (x = 0.0, 0.3, 0.6, and 0.9) sintered pellets synthesized by solid-state reaction method. The as-synthesized samples were analyzed using X-ray diffraction (XRD) and impedance spectroscopy. The emergence of orthorhombic phase fit into space group Pnmm was revealed by XRD, and the addition of Ca resulted in a considerable shift in grain size. Dielectric properties were determined using an impedance spectroscopy in a wide frequency range from 1MHz to 3 GHz. The dielectric properties i.e., dielectric constant (εr) and dielectric loss (tanσ), were measured at 3 GHz frequency. The frequency-dependent parameters such as conductivity, dielectric constant, and dielectric loss indicated that the relaxation process is a Maxwell–Wagner type of interfacial polarization. The improved dielectric properties and low energy loss have made (Ba1−xCax)Ti4O9 a prominent energy storage material. This study provides the possibility to improve its dielectric properties and reduce energy loss, making it an excellent energy storage material.

An effective way for the improvement of resonance frequency was demonstrated by the orientation of CoFe2O4 nanocubes (NCs) after applying a magnetic field. The magnetic holography image of the oriented CoFe2O4 NC arrays was obtained, and the vortex domain structure was found in single CoFe2O4 NCs, which greatly depends on dipolar interactions. Moreover, the cutting-off frequency of oriented CoFe2O4 NCs of 8.8 GHz is achieved with a slight increase in permeability at an extremely low mass fraction (about 10%). This work provides an effective way for optimizing the high-frequency properties of magnetic nanomaterials above GHz.