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Spintronic devices that utilize spin transfer torque are promising for integrated memory applications. However, these devices face substantial energy consumption challenges due to the high current densities required for switching. Conversely, voltage‐driven spintronic devices, using capacitive displacement charge, can realize switching operations that are energy‐efficient (≈1–10 fJ bit−1). This work investigates switching based on voltage control of the interlayer exchange coupling in perpendicular magnetic anisotropy (PMA) multilayered heterostructures. Unlike previous works that utilized gating techniques that employ ionic transport mechanisms to control interlayer exchange coupling, this study employs electrostatic gating by using MgO, which is more compatible with modern spintronic‐based memories. These results suggest that the magnetization anisotropy, and the magnitude, and phase of the Ruderman‐Kittel‐Kasuya‐Yosida (RKKY) coupling function with spacer layer thickness can be controlled through electric gating, providing a promising avenue for the development of energy‐efficient magnetic data storage devices. [ABSTRACT FROM AUTHOR]

We report the preparation and characterization of vanadium substituted four-layer Aurivillius compound Bi5Fe1.5V0.5Ti2O15 using spin coating method. Ferroelectricity in the prepared films are confirmed from the well saturated polarization vs electric field (P-E) loops having remnant polarization (2 Pr) around 12.94 µC/cm2 at room temperature. In addition, low temperature P-E measurements show a decrease in Pmax and 2 Pr, which is attributed to the stabilization of defect dipole complexes and domain pinning, as seen in bismuth-based ferroelectrics. Additionally, this decrease in polarization is accompanied by an increase in imprint, confirming the presence of defect dipoles manifested as internal fields. [ABSTRACT FROM AUTHOR]

The present work report synthesis of four-layer Aurivillius compound with systematic replacement of A-site Bi 3 + cation via La 3 + . Four-layer Aurivillius structure and phase purity is confirmed by x-ray diffraction measurements. Raman spectroscopy measurement indicate that La replaces Bi from perovskite like slab. M o ¨ ssbauer spectroscopy measurement shows the presence of paramagnetic behaviour at room temperature and confirms the presence of Fe 3 + in octahedral environment. Further, magnetization measurements indicate paramagnetic nature down to 5K similar to parent compound (Bi 5 FeTi 3 O 15 ) and suggest La substitution at A-site does not induce the magnetic ordering. [ABSTRACT FROM AUTHOR]

The present work deals with the calculation of electrocaloric (EC) coefficients of BaTi1-xSnxO3 (x = 0.15, 0.20, 0.30) polycrystalline ceramics. Dielectric and polarization studies are carried out in a temperature range of 100 − 300 K to calculate the EC coefficients employing the indirect method based on Maxwell's equations. It is demonstrated that the EC effect is enhanced near the dielectric maxima for all the samples, including that of samples which exhibit relaxor behavior (x = 0.30). Furthermore, the maximum change in temperature, the temperature at which the maximum EC coefficient is achieved and the working range for EC effect are shown to be tunable with electric field and Sn substitution. [ABSTRACT FROM AUTHOR]

The present work reports the structural, electrical and magnetic properties of W6+ and Mo6+ substituted four-layer Aurivillius compound, Bi5FeTi3O15 (BFTO). The oxidation states of the dopants and other elements of BFTO are studied from x-ray photo-electron and 57Fe Mössbauer spectroscopy. The substitution resulted in a net increase of magnetic cation (Fe3+) from 25% to about 37.5% in BFTO. However, the magnetization measurements indicate the lack of magnetic ordering even down to 2 K. Further, the high temperature (300-1070 K) dielectric study of these compounds reveal the ferroelectric transition temperature decreases with the increase of magnetic cations in BFTO because of hexavalent W6+ and Mo6+ substitution at Ti4+ site. [ABSTRACT FROM AUTHOR]

Here, we report detailed studies on magnetic phase transitions and magneto-electric (ME) coupling in Fe 1 - x Ce x VO 4 . X-ray diffraction (XRD) and Raman spectroscopic measurements confirm triclinic crystal structure (P-1) with small variation in lattice parameters and Ce incorporation into the FeVO 4 lattice up to 10% of Ce. The presence of local lattice distortions and electronic inductive effect in FeVO 4 between Fe 3 + and V 5 + ions were found in X-ray absorption near edge structure (XANES) studies due to the presence of Fe 3 + –O– V 5 + linkages. Two antiferromagnetic (AFM) transitions similar to FeVO 4 appear at 21.86 K and 16.03 K, and Ce doping has little effect on the magnetic transitions. 57 Fe Mössbauer spectroscopic results show the invariance of Fe valance. Low temperature high magnetic field Mössbauer data depicts the presence of spiral AFM order in all the samples. A sharp peak at 16.0 K in dielectric permittivity with minimal suppression due to applied magnetic field is observed indicating the presence of ferroelectricity and magneto-dielectric coupling. Magnetic and ME transitions are almost robust against Ce doping. [ABSTRACT FROM AUTHOR]