Field effect configuration (FEC) coupled field effect studies (FES) is one of the prime requisites for the development of spintronic based logic and memory devices having better sensitivities for external perturbations specifically while scaling down the technology. In this communication, LaMnO3-delta / La0.7Ca0.3MnO3 / LaAlO3 (LMO / LCMO / LAO) manganite - manganite composite structure was successfully fabricated using cost effective chemical solution deposition (CSD) method. FEC coupled FES have been performed across the electrically polarizable LMO layer and LCMO conducting channel. Enormous room temperature colossal electroresistance (CER) has been acquired similar to 7000 % under 2 MV/cm forward biased control electric field and similar to 8.5 x 10(5) % under 0.9 MV/cm reverse biased control electric field. Elegant modifications in the resistive behavior have been understood on the bases of charge carrier density alterations, interface modifications, phase separation, Mott-type phase transformation and formation-break down of depletion region across the manganite - manganite composite structure.

In recent years, thin films of weak ferromagnetic materials have been in huge demand; however, probing their magnetic characteristics has been difficult due to contributions from underlying substrates. In the present study, we have analyzed the magnetic properties of the commonly used single-crystal SrTiO3 (100) and LaAlO3 (100) substrates and performed a time-dependent annealing protocol in vacuum and ambient oxygen pressure to mitigate the intrinsic weak ferromagnetic contributions from these substrates arising due to the presence of disorder or defects such as vacancies in the pristine substrates. It is shown that after proper air annealing, the substrate magnetic background becomes diamagnetic. When such air-annealed diamagnetic substrates are used for the deposition of low-thickness films carrying low magnetic moments such as SrRuO3 and SrMnO3 thin films, their magnetic transitions are explicitly observed. The proposed annealing protocols help to improve the signal from weak magnetic samples. This allows us to analyze the film's magnetic properties without worrying about the contribution from the substrate.

Competition between spin–orbit interaction and electron correlation can stabilize a variety of non-trivial electronic and magnetic ground states.

The phenomena of resistive switching (RS) or memristive devices is of great interest with the rise of emerging technologies and applications. It provides a remarkable approach to control the electronic phase of correlated electronic systems for the new generation Mottronic devices. Here, we have studied the RS properties of epitaxial V2O3 thin film grown on Al2O3 substrate at low temperature by recording the current biased voltage-current characteristics (I-V) within hysteretic phase co-existence region of the Mott transition. The temperature dependent Raman analysis reveal a structural phase transition accompanied with the Mott transition. Interestingly, our I-V characteristics demonstrate a clear thermally triggered insulator-to-metal transition (IMT). It is divulged that Joule heating is a dominating factor for triggering the electrically induced RS. Control of conductivity provides a pathway for adaptable electronics based on memristive concepts.

Ferromagnetic insulators (FMIs) have widespread applications in microwave devices, magnetic tunneling junctions, and dissipationless electronic and quantum-spintronic devices. However, the sparsity of the available high-temperature FMIs has led to the quest for a robust and controllable insulating ferromagnetic state. Here, we present compelling evidence of modulation of the magnetic ground state in a SrCoO2.5 (SCO) thin film via strain engineering. The SCO system is an antiferromagnetic insulator with a Neel temperature, TN, of ∼550 K. Applying in-plane compressive strain, the SCO thin film reveals an insulating ferromagnetic state with an extraordinarily high Curie temperature, TC, of ∼750 K. The emerged ferromagnetic state is associated with charge-disproportionation (CD) and spin-state-disproportionation (SSD), involving high-spin Co2+ and low-spin Co4+ ions. The density functional theory calculation also produces an insulating ferromagnetic state in the strained SCO system, consistent with the CD and SSD, which is associated with the structural ordering in the system. Transpiring the insulating ferromagnetic state through modulating the electronic correlation parameters via strain engineering in the SCO thin film will have a significant impact in large areas of modern electronic and spintronic applications.

Mott-insulator-to-metal transitions under an applied electric field are currently the subject of numerous fundamental and applied studies. Exploring the electronic parameters contributing to the external control of conductivity of correlated systems like V2O3 is an indispensable requirement for next-generation Mottronic devices. Here, we demonstrate a resistive-switching (RS) phenomenon, i.e., a flip from the high-resistance state (HRS) to the low-resistance state in a V2O3 thin film grown on Si (001) substrate by applying a dc voltage as external perturbation. The RS effect is explained in connection with the electronic structure by overcoming the electronic correlations and, in the HRS, the V2O3/Si film is realized to lie in the intermediate regime between the Mott-Hubbard and charge-transfer insulating states. Interestingly, our study reveals an electrically induced nonthermal RS effect in the V2O3/Si film in terms of different energetics like on-site Coulomb repulsion (U) and charge-transfer energy (A), which regulate the exotic properties of this metal oxide and its functionality.

We have probed the effect of intrinsic strain on the structural and magnetic properties of magneto-electric hexagonal Sr0.6Ba0.4MnO3 (SBMO) thin film grown by pulsed laser deposition on LaAlO3 (1 1 0) substrate by varying oxygen partial pressure (OPP). While the grown films show hexagonal structure with varying OPP, transition from oriented to polycrystalline growth is observed with increase in OPP. Raman spectroscopy confirms the P63/mmc symmetry of grown films along with the indication of distortion of octahedral. Magnetization measurements reveal room temperature weak ferromagnetic behavior in the thin films, which is in contrast to antiferromagnetic nature of its bulk counterpart. X-ray magnetic circular dichroism measurement confirms weak ferromagnetic behavior with contribution from unquenched orbital magnetic moment.

Understanding the electronic structure of photocatalysts is crucial for enhancing their efficiency. In this study, we have successfully synthesized novel monoclinic bismuth vanadate (Bi 7 VO 13 ) nanoparticles using the gas phase condensation technique, with an average particle size of 40 nm. To investigate the crystallographic structure of the as-synthesized nanoparticles, we conducted X-ray diffraction (XRD) experiments. Additionally, we employed advanced characterization techniques to provide a detailed analysis of the electronic structure of Bi 7 VO 13 nanoparticles. This study presents the first report on the electronic structure of Bi 7 VO 13 nanoparticles using the aforementioned spectroscopic methods. Remarkably, the investigation revealed that the valence band maximum (VB) and conduction band minimum (CB) are dominated by O 2p and V 3d states, respectively. Moreover, X-ray absorption spectroscopy (XAS) reveals splitting the V 3d conduction band state into a triplet d-manifold at the V L-edge and O K-edge. This splitting arises from the lattice distortion induced by lone pairs, which gives rise to a band gap of 2.28 eV. Under visible light irradiation, the Bi 7 VO 13 nanoparticles exhibit efficient visible light absorption, highlighting their potential for photocatalytic applications. Notably, our experiments demonstrated outstanding photodegradation properties of methylene blue, serving as a model effluent, further underscoring the photocatalytic progress of Bi 7 VO 13 nanoparticles. In conclusion, this research explains the functioning of Bi 7 VO 13 photocatalysts and opens the doors for utilizing their potential to generate a cleaner and brighter future.

The three-dimensional (3D) nanosized compactness of devices is in high demand for the spintronic-device applicability. However, very few self-organized, periodic magnetic 3D nanostructures of transition metal oxides are known. Here, we report the direct microscopic evidence of a self-assembled, square-shaped, periodic array of coherent orthogonal nanoblock-type structure in an epitaxial SrRuO3 (SRO) thin film (∼90 nm thickness) grown on (001) LaAlO3 (LAO) using pulsed-laser deposition technique. The evolution of different growth facets of SRO over the LAO single crystalline substrate with different thickness are observed. The combined effect of substrate-induced strain and misfit is utilized to grow such self-assembled, ordered nanostructure. The spontaneous formation of such ordered ferromagnetic nano-devices can fill the gap of a miniaturized spintronic device for magnetic memory-based applications.

Multiferroic materials have undergone extensive research in the past two decades in an effort to produce a sizable room-temperature magneto-electric (ME) effect in either exclusive or composite materials for use in a variety of electronic or spintronic devices. These studies have looked into the ME effect by switching the electric polarization by the magnetic field or switching the magnetism by the electric field. Here, an innovative way is developed to knot the functional properties based on the tremendous modulation of electronics and magnetization by the electric field of the topotactic phase transitions (TPT) in heterostructures composed of metallic-magnet/TPT-material. It is divulged that application of a nominal potential difference of 2-3 Volts induces gigantic changes in magnetization by 100-250% leading to colossal Voltomagnetic effect, which would be tremendously beneficial for low-power consumption applications in spintronics. Switching electronics and magnetism by inducing TPT through applying an electric field requires much less energy, making such TPT-based systems promising for energy-efficient memory and logic applications as well as opening a plethora of tremendous opportunities for applications in different domains.

The present study reports the modifying the properties of carbon quantum dots/titanium dioxide (CQDs/TiO2, termed as CT) nanocomposite by Nitrogen (N+) ion beam irradiation in the energy range of 10 keV-40 keV at a fluence of 3 x 10(15) ions cm(-2). Transmission electron microscopic results reveals the anchoring of (3-5) nm CQDs on TiO2 nanoparticles of size similar to 25 nm. UV-Visible spectroscopic results show the decrease in the bandgap of CT nanocomposite after N+ ion irradiation. X-ray Diffractogram exhibits the shift in the planes of CT nanocomposite due to irradiation. X-ray photoelectron spectroscopic results indicate the presence of nitrogen functional groups after irradiation. Raman spectroscopy results reveal the enhancement in disorder parameters due to irradiation-induced large number of small sp(2) domains of carbon. Photoluminescence spectroscopy results show the decrease in emission intensity of CT nanocomposite after irradiation due to suppression in the recombination rate of photoexcited electron-hole pairs. The work function of CT nanocomposite decreases after ion irradiation indicating the shifting of Fermi energy level towards conduction band as studied by Ultraviolet photoelectron spectroscopy. Photoelectrochemical measurement studies reveals that improvement in the photoelectrochemical performance of 40 keV N+ ion irradiated CT compared to TiO2.

We report a facile synthesis of nitrogen and phosphorus co-doped carbon quantum dots (NPCQDs) anchored on ZnO nanorods to form NPCQDs/ZnO (NPCZ) nanohybrid as efficient and robust photocatalysts for light-driven hydrogen production. The synthesized NPCZ catalyst exhibited improvement in hydrogen production of 417 μmolh−1g−1 under visible light compared to nitrogen doped CQDs/ZnO (NCZ), phosphorus doped CQDs/ZnO (PCZ) and CQDs/ZnO (CZ) nanohybrid photocatalysts. The synergistic interactions between NPCQDs and ZnO nanorods give rise to the formation of additional energy levels, decrease in recombination rate and increase in decay lifetime of photo-generated electron hole pairs, reduced work function, thus the eventual improved hydrogen generation performance in visible region. Further, the experimentally obtained results are consistently corroborated by the first principles Density Functional Theory (DFT), revealing the decrease in bandgap as well as work function and improvement in density of states (DOS) of NPCZ photocatalyst.

Na2IrO3 (NIO) is known to be a spin-orbit (SO) driven j=1/2 pseudo-spin Mott-Hubbard (M-H) insulator. However, the microscopic origin of the pseudo-spin state and the role of local structural distortions have not been clearly understood. Using a combination of theoretical calculations and x-ray spectroscopy, we show that the energetics in the vicinity of Fermi level (EF) is governed by SO interactions, electron correlation and local octahedral distortions. Contrary to the earlier understanding, here we show that the j=3/2 and 1/2 pseudo-spin states have admixture of both t2g and eg characters due to local structural distortion. Reduction of local octahedral symmetry also enables Ir 5d- O2p hybridization around the EF resulting in a M-H insulator with enhanced charge transfer character. The possibility of Slater insulator phase is also ruled out by a combination of absence of room temperature DoS in valence band spectra, calculated moments and temperature dependent magnetization measurements.

Magnetoelastic and magnetoelectric coupling in the artificial multiferroic heterostructures facilitate valuable features for device applications such as magnetic field sensors and electric-write magnetic-read memory devices. In ferromagnetic/ferroelectric heterostructures, the intertwined physical properties can be manipulated by an external perturbation, such as an electric field, temperature, or a magnetic field. Here, we demonstrate the remote-controlled tunability of these effects under visible, coherent, and polarized light. The combined surface and bulk magnetic study of domain-correlated Ni/BaTiO3 heterostructures reveals that the system shows strong sensitivity to the light illumination via the combined effect of piezoelectricity, ferroelectric polarization, spin imbalance, magnetostriction, and magnetoelectric coupling. A well-defined ferroelastic domain structure is fully transferred from a ferroelectric substrate to the magnetostrictive layer via interface strain transfer. The visible light illumination is used to manipulate the original ferromagnetic microstructure by the light-induced domain wall motion in ferroelectric substrates and consequently the domain wall motion in the ferromagnetic layer. Our findings mimic the attractive remote-controlled ferroelectric random-access memory write and magnetic random-access memory read application scenarios, hence facilitating a perspective for room temperature spintronic device applications.

Artificial multiferroics provide a tunable magnetoelastic and magnetoelectric coupling owing to the variety of combinations of ferroelectric and ferromagnetic layers, hence facilitate a better perspective for device applications such as magnetic field sensors and electric write magnetic -read memory devices. The intertwined physical properties can be controlled via external parameters such as electric field, temperature, and magnetic field. Here, we report an additional mode to manoeuvre the magnetoelastic and magnetoelectric coupling in an epitaxial SrRuO3/BaTiO3 multiferroic heterostructure using polarized visible light illumination. The light-induced ferroelastic (FE) domain wall motion in underlying BaTiO3 leads to photostriction and photodomain effects. Consequently, the change in the converse magnetoelastic effects leads to modify the magnetic properties of the above grown SrRuO3 layer. Besides this, we have observed a sharp and persistent changes in the SrRuO3/ BaTiO3 heterostructure, when the system is electrically biased owing to the change in the interfacial converse magnetoelectric coupling. Light controlled magnetization tunability in BaTiO3-based artificial multiferroic can open an alternate way for potential applications in several types of wireless devices and magnetic field sensors, electric write magnetic-read memory devices and other interesting optomechanical systems. Our findings in this context can be proven indeed as a novel prospective for opto-spintronics device applications.

Control over the movements of free charge carriers across any manganite based interface can functionalize the device for spintronic applications.

In this communication, LaMnO3/La0·7Ca0·3MnO3/LaAlO3 (LMO/LCMO/LAO) structure was prepared by low cost sol–gel based chemical solution deposition (CSD) method. Field effect configuration (FEC) based LMO/LCMO interface resistive nature has been investigated for the LMO/LCMO/LAO structure. Temperature dependent interface resistivity modulation factor has been understood using forward and reverse bias modes. Temperature dependent LMO/LCMO interface resistivity has been discussed in detail under different applied magnetic fields, different applied interface electric fields and different magnetic field directions to identify simultaneous possible existence of magnetoresistance (MR), electroresistance (ER) and anisotropic magnetoresistance (AMR) effects across the same LMO/LCMO interface. Zener double exchange (ZDE) polynomial law has been fitted theoretically to the obtained interface resistive nature to understand the possible spin fluctuations across the LMO/LCMO interface.

Recently, hybrid supercapacitors gained the interest of energy experts because of their high energy/power density and long lifespan. In this manuscript, Zn1-xNdxO (x = 0.00, 0.01, 0.03, and 0.05) nanoparticles were synthesised using the microwave assisted co-precipitation method and characterized using XRD, Raman, TEM, XAS, and electrochemical analyses.The HR-TEM images confirmed that all of the samples exhibited spherical morphologies with average particle sizes in the range of 17-20 nm. The XRD and Raman spectroscopy studies infer that crystallinity enhances with increase in the doping concentration. The Nd ions were revealed to possess a valence state of +3, while the Zn ions had a valence state of +2, confirmed from XAS analyses. The electro-chemical analysis showed that 3 % Nd-doped ZnO electrode exhibited the maximum specific capacitance (SC) of 154 F/g, at a current density of 2.5 A/g and the best cycle stability when compared to the undoped and other Zn1-xNdxO samples (retaining 92 % after 1000 cycles). The specific capacitance of undoped ZnO determined at a current density of 2.5 A/g was found to be 21 F/g. The energy density and specific power of a 3 % Nd3+-doped ZnO supercapacitor were measured at 7.36 Wh/kg and 730 W/kg, respectively. The electrochemical results suggest that Nd3+-doped ZnO material would serve as an electrode material for supercapacitors application.

The structural, electronic and magnetic properties of anti-site disordered Sm$ _{2} $NiMnO$ _{6} $ double perovskite has been studied. RE$_{2}$NiMnO$_{6}$ (RE: rare-earth) ordered double perovskite is commonly believed to show two distinct magnetic phase transitions viz, paramagnetic to ferromagnetic (FM) transition at T = T$ _{C} $ due to Ni-O-Mn super exchange interaction and another transition at T = T$ _{d} $ due to coupling of RE spins with Ni-Mn network. In our present study, we have observed that the presence of intrinsic B-site disorder results in an additional antiferromagnetic (AFM) coupling, mediated via Ni-O-Ni and Mn-O-Mn local bond pairs. As a consequence, the magnetic behavior of SNMO comprises of co-existing FM-AFM phases, which are respectively governed by the anti-site ordered and disordered structures. Field dependent inverted cusp like trend in M(T) and two step reversible loop behavior in M(H) measurements indicate the presence of competing FM-AFM phases over a wide range of temperature values (T$ _{d} < $ T $ < $ T$ _{C} $).