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Magnetic Tunnel Junction-based molecular spintronics devices (MTJMSDs) hold great potential for integrating paramagnetic molecules with ferromagnetic electrodes, creating a diverse array of metamaterials with novel magnetic behaviors. Understanding interactions, especially between molecules and electrode materials, is essential to advancing this field. In this study, we used Monte Carlo simulation (MCS) to examine the influence of Dzyaloshinskii-Moriya interaction(DMI) on the MTJMSDs. Our simulations reveal that the presence of DMI interaction significantly lowered the magnetization of the ferromagnetic (FM) electrode. This DMI effect on the FM electrode provides a potential mechanism to explain the experimental observations of losing magnetic contrast on one FM electrode of the MTJMSD. A cross-junction-shaped MTJMSD, where several thousands of paramagnetic Octametallic Molecular Complexes are covalently bonded between two FM electrodes along the junction edges, exhibited loss of magnetic contrast on one ferromagnet in MFM imaging. DMI's impact on FM electrode properties resembles the experimental observation on MTJMSD. Our MCS showed that the strong DMI induced alternating magnetic bands aligned in opposite directions on a ferromagnetic electrode. Molecule bridges transported the effect of the DMI-induced magnetic phases onto the FM electrode connected to the other end of the molecule. For the specific range of DMI, the direction of magnetization of the FM electrode present on the other end of the molecular channel could switch based on the nature of the DMI-induced magnetic phase present in the junction area. This study underscores the importance of antisymmetric interactions, like DMI, in influencing the magnetic properties of MTJMSD systems. In future MSD experimental studies, DMI on FM electrodes can be achieved by using suitable molecule-FM interfaces or multilayer FM electrodes harnessing spin-orbit coupling. MTJMSD test bed provides excellent opportunities for creating unprecedentedly strong molecule-FM electrode coupling and using multilayer electrodes. 

Magnetic tunnel junctions (MTJs) can integrate novel single molecular device elements to overcome long-standing fabrication challenges, thus unlocking their novel potential. This study employs magnetic force microscopy (MFM) to demonstrate that organometallic molecules, when placed between two ferromagnetic electrodes along cross-junction shaped MTJ edges, dramatically altered the magnetic properties of the electrodes, affecting areas several hundred microns in size around the molecular junction vicinity at room temperature. These findings are supported by magnetic resonance and magnetometer studies on ∼7000 MTJ pillars. MFM on the pillar sample showed an almost complete disappearance of the magnetic contrast. The spatial magnetic image suggests that molecular channels significantly impacted the spin density of states in the ferromagnetic electrodes. This advancement in MTJ-based molecular devices paves the way for a new generation of commercially viable logic and memory devices controlled by molecular quantum states at near-room temperatures. 

Magnetic tunnel junction-based molecular spintronic devices (MTJMSDs) hold promises for the creation of novel magnetic metamaterials. By coupling molecules with magnetic electrodes, MTJMSDs can exhibit unique magnetic properties and enable new magnetic phenomena. Understanding the interactions between molecules and electrode materials is essential for optimizing device performance. This paper presents a Monte Carlo Simulation (MCS) study of MTJMSDs, focusing on the impact of the Dzyaloshinskii-Moriya interaction (DMI). In the proposed system, a molecule is positioned between ferromagnetic (FM) and antiferromagnetic (AFM) electrodes. The DMI strength of the individual electrodes is varied independently to probe its impact on the magnetic properties of the electrodes and the overall MTJMSD. The simulations reveal that the FM electrode loses its magnetization entirely at the highest DMI values, consistent with our previous experimental observations where one of the FM electrode's magnetic identities disappeared following molecular treatment. Additionally, the magnetic moments of molecules decreased from 11 to 1 a.u. as the DMI increased in the FM electrode. The DMI-induced peculiar magnetic contrasts in the form of band structures are also investigated on both electrodes. This study highlights the significance of antisymmetric interactions, such as DMI, in determining the behavior of MTJMSDs and provides insights into how these interactions influence device properties across different magnetic phases. 

Single-molecule magnets (SMMs) are pivotal in molecular spintronics, showing unique quantum behaviors that can advance spin-based technologies. By incorporating SMMs into magnetic tunnel junctions (MTJs), new possibilities emerge for low-power, energy-efficient data storage, memory devices and quantum computing. This study explores how SMMs influence spin-dependent transport in antiferromagnet-based MTJ molecular spintronic devices (MTJMSDs). We fabricated cross-junction MTJ devices with an antiferromagnetic Ta/FeMn bottom electrode and ferromagnetic NiFe/Ta top electrode, with a ∼2 nm AlOx layer, designed so that the AlOx barrier thickness at the junction intersection matched the SMM length, allowing them to act as spin channels bridging the two electrodes. Following SMM treatment, the MTJMSDs exhibited significant current enhancement, reaching a peak of 40 μA at 400 mV at room temperature. In contrast, bare MTJ junctions experienced a sharp current reduction, falling to the pA range at 0°C and remaining stable at lower temperatures—a suppression notably greater than in SMM-treated samples (Ref: Sankhi et al., Journal of Magnetism and Magnetic Materials, p. 172608, 2024). Additional vibration sample magnetometry on pillar shaped devices of same material stacks indicated a slight decrease in magnetic moment after incorporating SMMs, suggesting an effect on magnetic coupling of molecule with electrodes. Overall, this work highlights the promise of antiferromagnetic materials in optimizing MTJMSD devices and advancing molecular spintronics. 

Abstract With the aim of developing fuel cell applications that are capable of generating efficient electrical energy, much of the attention should be given to exploring new catalysts that could be less costly and more abundant than the most commonly used catalyst, platinum. This work explores nickel-based layered double hydroxide (Ni-LDH) as a fuel cell’s affordable catalyst for Oxygen Reduction Reaction (ORR). Ni-LDH was prepared and drop coated onto a Glassy Carbon Electrode (GCE) to conduct a 3-way electrode cyclic voltammetry using an oxygen-saturated aqueous sodium hydroxide (NaOH) solution as electrolyte. The electroanalytical study of the GCE-modified Ni-LDH working electrode showed an enhancement of both anodic and cathodic peaks because of the presence of oxygen at low temperatures. Data obtained from this experiment will serve as a reference for fuel cell systems in which Ni-LDH modified working electrodes are scaled up for comparison of area-specific properties.