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The current study delivers the first assessment of well-separated cone shaped n-type epitaxial BiFe0.9Mn0.1O3 (n-BFMO) shells integrated on LaNiO3 (LNO) buffered vertical arrays of p-type nanoporous Si nanowire cores as an absorber for high efficiency and sustainable all- oxide photovoltaic devices. The photovoltaic effect of the LNO/n-BFMO/Au radial heterojunction is investigated by registering the current-voltage curves under AM 1.5 (100 mW cm-2) illumination conditions at various ferroelectric polarization states of BFMO. The as-deposited LNO/BFMO/Au nanowire arrays fabricated by scalable Pulsed Laser deposition are completely self-polarized and produced a remarkably large open circuit photovoltage up to 0.53V under zero poling condition. The direction of photocurrent and photovoltage is reversibly switchable in response to ferroelectric polarization switching. The short circuit photocurrent "ISC" and open circuit voltage "VOC" depict a hysteresis loop which is more or less identical to that of ferroelectric polarization and thus can be utilized as a nondestructive optical readout of the ferroelectric nonvolatile memories. By introducing special architecture for the BFO based photovoltaic device, a photoconversion efficiency ~0.3% and External Quantum Efficiency ~11% are achieved at zero polarization state, which can further be enhanced and modulated to ~0.6% and 14%, respectively, at the negative poling state of BFMO. [ABSTRACT FROM AUTHOR]

The strain mediated electrical and magnetic properties were investigated in PZT/Ni-Mn-In heterostructure deposited on Si (100) by dc/rf magnetron sputtering. X-ray diffraction pattern revealed that (220) orientation of Ni-Mn-In facilitate the (110) oriented tertragonal phase growth of PZT layer in PZT/Ni-Mn-In heterostructure. A distinctive peak in dielectric constant versus temperature plots around martensitic phase transformation temperature of Ni-Mn-In showed a strain mediated coupling between Ni-Mn-In and PZT layers. The ferroelectric measurement taken at different temperatures exhibits a well saturated and temperature dependent P-E loops with a highest value of Psat∼55 μC/cm2 obtained during martensite-austenite transition temperature region of Ni- Mn-In. The stress induced by Ni-Mn-In layer on upper PZT film due to structural transformation from martensite to austenite resulted in temperature modulated Tunability of PZT/Ni-Mn-In heterostructure. A tunability of 42% was achieved at 290K (structural transition region of Ni-Mn-In) in these heterostructures. I-V measurements taken at different temperatures indicated that ohmic conduction was the main conduction mechanism over a large electric field range in these heterostructures. Magnetic measurement revealed that heterostructure was ferromagnetic at room temperature with a saturation magnetization of ∼123 emu/cm3. Such multiferroic heterostructures exhibits promising applications in various microelectromechanical systems. [ABSTRACT FROM AUTHOR]

In the present study, structural and magnetic properties of Mn-rich, off-stoichiometric, nanocrystalline Ni–Mn–Sn ferromagnetic shape memory alloy thin films, grown on Si (100) substrates at 550 °C by dc magnetron sputtering have been systematically investigated. The crystallization, surface morphology, and structural features were studied using x-ray diffraction, atomic force microscopy, and field emission scanning electron microscopy. The structural transition from austenite to martensite was observed with an increase of Mn content. Austenitic phase with mixed L21/A2+B2 structure has been observed at room temperature in Ni52.6Mn23.7Sn23.6 (S1) and Ni51.5Mn26.1Sn22.2 (S2) films, while those with composition of Ni58.9Mn28.0Sn13.0 (S3) and Ni58.3Mn29.0Sn12.6 (S4) show martensitic phase with 14M modulated monoclinic structures. Field induced martensite-austenite transformation has been observed in magnetization studies using superconducting quantum interference device magnetometer. Temperature dependent magnetization measurements demonstrate the influence of magnetic field on the structural phase transition temperature. The investigations reveal an increase of martensitic transformation temperature (TM) with corresponding increase in substitution of Mn. The films exhibit ferromagnetic behavior at low temperatures below Curie temperature (TC). The decrease in saturation moment with increasing Mn content, indicates the existence of antiferromagnetic correlations within ferromagnetic matrix. [ABSTRACT FROM AUTHOR]

Nanocrystalline V2O5 thin films have been grown at low temperature on glass substrates by dc magnetron sputtering using a vanadium metal target. Film thickness was found to have a great impact on the orientation, shape, and size of the crystallites of these films. X-ray diffraction (XRD) patterns of the films with a thickness of 110 nm show a strong c-axis orientated crystal structure with a preferred (001) orientation, while those with a thickness of 315 nm show mixed orientations (a-axis+c-axis). With further increase in film thickness, an a-axis orientation with predominant (200) reflection was observed in the XRD pattern. The shape of the crystallite changes from a rodlike to a bricklike structure with change in crystallographic orientation from (001) to (200). Atomic force microscopy results were also in agreement with the field emission scanning electron microscopy and XRD results. A direct correlation has been established between the semiconductor to metal transformation of V2O5 films and their crystallite size and orientation. The optical measurement also revealed a systematic band gap variation (from 2.50 to 2.20 eV) with variation in film thickness. [ABSTRACT FROM AUTHOR]

A detail study was conducted to determine the influence of film thickness on structural, electrical, and optical properties of nanocrystalline [V.sub.2][O.sub.5] thin films deposited by dc magnetron sputtering on glass substrate. Film thickness was found to have great impact on the orientation, shape, and size of the crystallites of the films.