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We have fabricated the ZnFe2O4/ZnO (ZFO/ZnO) heterostructure on a silicon substrate by pulsed laser deposition technique and studied the magnetization switching by the electric field in the ZFO/ZnO heterostructure using an indigenously developed optical cantilever beam magnetometer setup. The magnetization (M) vs electric field (E) curve reveals that the magnetization of the ZFO film has been switched by an electric field applied along the thickness of the ZnO film. The saturation magnetization is found to be 28.77 MA/m from the M–E curve. The emergence of electric field-driven magnetization switching in the ZFO/ZnO heterostructure is attributed to the strain-mediated magnetoelectric coupling between the electric polarization of the ZnO film and the magnetization of the ZFO film as evidenced by the butterfly-type hysteresis behavior of magnetization with the applied electric field. However, the realization of electric field-controlled magnetization switching in the ZFO/ZnO heterostructure is regarded as a potential aspect for the fabrication of energy-efficient spintronic devices such as magnetoelectric random access memory cells, highly sensitive magnetic field sensors, magneto-logic devices, and neuromorphic devices. [ABSTRACT FROM AUTHOR]

A polycrystalline ZnO film is grown on a silicon substrate by the pulsed laser deposition method, and the electric field-induced magnetization in ZnO using an optical cantilever beam magnetometer setup is studied. The magnetization vs bipolar dc electric field measurements reveal the occurrence of magnetization switching in the ZnO film. The magnetization switching in the presence of an electric field is ascribed to the converse magnetoelectric (ME) coupling that takes place between the electrical and the magnetic order parameters existing in the ZnO film. We have found the strain-driven magnetization change as evidenced by the butterfly shape of the magnetization vs the electric field curve. A saturation magnetization of 13.31 MA/m is obtained. Moreover, a significant value of the ME coupling coefficient (α) (1.61 × 10−7 s/m) has also been reported in this article. The emergence of electric field-induced magnetization in a single polycrystalline ZnO film is regarded to be a very promising aspect in designing high-density energy-efficient spintronic and different multifunctional devices. [ABSTRACT FROM AUTHOR]

We have investigated the in-plane and out-of-plane magnetostriction (λ) and strain sensitivity (d λ / dH) of the polycrystalline ZnFe2O4 (ZFO) film on an Si(100) substrate at room temperature using the optical cantilever beam magnetometer. A remarkable enhancement in magnetostriction (129.34%) and strain sensitivity (218.49%) is obtained in the out-of-plane configuration in comparison with the same in the in-plane configuration. The film possesses a high positive magnetostriction (strain sensitivity) of 325.67 ± 0.42 ppm (4.65 × 10 − 9 A − 1 m) and 746.92 ± 1.18 ppm (14.81 × 10 − 9 A − 1 m) for in-plane and out-of-plane geometry, respectively, at room temperature. The huge enhancement in magnetostriction and strain sensitivity is ascribed to the shape anisotropy of the ZFO/Si composite in the out-of-plane configuration, and thus, the out-of-plane configuration would be highly potential in designing magnetic actuators, magnetic memory devices, and bio-medical devices at room temperature. [ABSTRACT FROM AUTHOR]

The optical cantilever beam magnetometer (CBM) setup was used to investigate the angle-dependent in-plane magnetostriction of a polycrystalline CoFe2O4 (CFO) film at room temperature (300 K). We observed compressive and tensile magnetostriction switching in rotation (θ) of magnetic field in the plane of the polycrystalline CFO film. At lower angles, the film exhibits the compressive nature of magnetostriction. However, as the angle of rotation increases, the compressive behavior decays continuously and switches to tensile nature at θ = 35°, and the tensile nature continues to grow up to the angle, θ = 45°. Further rotation of the magnetic field causes the tensile nature of magnetostriction to decline and, at θ = 60°, it switches back to the compressive nature of magnetostriction. The coexistence of compressive and tensile magnetostriction in the polycrystalline CFO film makes it a potentially suitable candidate for designing both sensors and actuators, and thus the film finds a way in developing novel smart materials. [ABSTRACT FROM AUTHOR]

The polycrystalline CoFe2O4 (CFO) film on cantilever substrate of silicon was grown using pulsed laser deposition (PLD) method and investigated its in-plane and out-of-plane magnetostrictive strain at room temperature (300 K) using the indigenous optical Cantilever Beam Magnetometer (CBM). The film shows a high compressive magnetostrictive strain of ‒ 387 ppm and ‒ 708 ppm for in-plane and out-of-plane configurations, respectively. Considerably, the magnetostrictive strain loops (λ‒H) possess a certain degree of hysteresis with a symmetric butterfly shape. The origin of large compressive magnetostriction of CFO film is attributed to the non-180° domain wall motion followed by 90° domain rotation. The large values of saturation magnetostrictive strain make CFO film a suitable candidate in sensor design for different purposes. [ABSTRACT FROM AUTHOR]

Coir dust reinforced polymer composites are prepared with epoxy resin as the matrix. The dielectric parameters (relative permittivity ε′, dielectric loss ε′′), AC conductivity σ, and resistivity ρ of pure epoxy resin and composites with different weight percent of coir dust were obtained in a frequency range of 100 Hz to 1 MHz, and temperature range of 30—150°C. The experimental results show that ε′, ε′′, and σ are increased and ρ is decreased with the addition of coir dust in epoxy resin. It is also observed that the dielectrical properties of the composites showed a strong dependence on frequency and temperature. The ε′ and ε′′ increases with increasing temperature because of greater movement of the dipole molecular chains and decreases with increasing frequency due to the orientation polarization. The conductivity of the composite is increased, and the resistivity of composite is decreased with increasing frequency. [ABSTRACT FROM AUTHOR]