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Abstract The objective of the experimental work is to enhance the machining capability of electrical discharge machining by suspending equal proportion of metal powders such as, molybdenum, nickel, and chromium in EDM 30 oil. Three different control factors such as peak current, pulse on time and powder concentration were varied to analyze the response factors namely material removal rate, surface roughness and radial overcut. The cause of powders concentration on material removal rate (MRR), surface roughness (SR), and radial overcut (ROC) have been investigated. An electron dispersive spectroscopy was utilized to investigate the surface revealed the deposition of nickel and chromium in the machined surface. Machined surface was focused to atomic force microscopy and scanning electron microscopy. Analysis of variance (ANOVA) results showed that peak current is the foremost factor in affecting MRR, SR and ROC.

The impact of orange peel coupling on spin current induced magnetization switching in a Co/Cu/Ni-Fe nanopillar device is investigated by solving the switching dynamics of magnetization of the free layer governed by the Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation. The value of the critical current required to initiate the magnetization switching is calculated analytically by solving the LLGS equation and verified the same through numerical analysis. Results of numerical simulation of the LLGS equation using Runge-Kutta fourth order procedure shows that the presence of orange peel coupling between the spacer and the ferromagnetic layers reduces the switching time of the nanopillar device from 67 ps to 48 ps for an applied current density of 4 × 1012Am−2. Also, the presence of orange peel coupling reduces the critical current required to initiate switching, and in this case, from 1.65 × 1012Am−2 to 1.39 × 1012Am−2.

A key task in the fact-checking workflow is to establish whether the claim under investigation has already been debunked or fact-checked before. This is essentially a retrieval task where a misinformation claim is used as a query to retrieve from a corpus of debunks. Prior debunk retrieval methods have typically been trained on annotated pairs of misinformation claims and debunks. The novelty of this paper is an Unsupervised Method for Training Debunked-Narrative Retrieval Models (UTDRM) in a zero-shot setting, eliminating the need for human-annotated pairs. This approach leverages fact-checking articles for the generation of synthetic claims and employs a neural retrieval model for training. Our experiments show that UTDRM tends to match or exceed the performance of state-of-the-art methods on seven datasets, which demonstrates its effectiveness and broad applicability. The paper also analyses the impact of various factors on UTDRM's performance, such as the quantity of fact-checking articles utilised, the number of synthetically generated claims employed, the proposed entity inoculation method, and the usage of large language models for retrieval. [ABSTRACT FROM AUTHOR]

A nanostrip magnonic-crystal waveguide with spatially periodic width modulation can serve as a gigahertz-range spin-wave filter. Compared with the regular constant-width nanostrip, the periodic width modulation creates forbidden bands (band gaps) at the Brillouin zone boundaries due to the spin-wave reflection by the periodic potential owing to the long-range dipolar interactions. Previous works have shown that there is a critical challenge in tuning the band structures of the magnonic-crystal waveguide once it is fabricated. In this work, using micromagnetic simulations, we show that voltage-controlled magnetic anisotropy can effectively tune the band structures of a ferromagnetic–dielectric heterostructural magnonic-crystal waveguide. A uniformly applied voltage of 0.1 V/nm can lead to a significant frequency shift of ~9 GHz. A spin-wave transistor prototype employing such a kind of spin-wave filter is proposed to realize various logical operations. Our results could be significant for future magnonic computing applications. [ABSTRACT FROM AUTHOR]

Antidot lattices made of magnetic thin films are good candidates to be employed in future magnetic recording media. In this manuscript we present a study on the effect of shape and field-induced magnetic anisotropies on the magnetization reversal of 10 nm and 50 nm thick permalloy antidot lattices. Rounded antidot square lattices were fabricated using a combination of electron beam evaporation and laser interference lithography, covering surfaces of a few cm2. We demonstrate that a magnetic anisotropy induced in the samples, as a consequence of an applied magnetic field during growth, competes with the shape anisotropy that dominates the response of the patterned thin films, and that the effect of the field-induced magnetic anisotropy scales with the thickness of the antidot thin films. Finally, we have quantified the anisotropy constant attributable to the uniaxial field-induced magnetic anisotropy in our antidot lattices. These findings are supported by micromagnetic simulations performed using MuMax3. [ABSTRACT FROM AUTHOR]

In this work we performed a detailed numerical analysis on the static and dynamic properties of magnetic antidot arrays as a function of their geometry. In particular, we explored how by varying the shape of these antidot arrays from circular holes to stadium-shaped holes, we can effectively control the magnetic properties of the array. Using micromagnetic simulations we evidenced that coercivity is very sensitive to the shape of antidots, while the remanence is more robust to these changes. Furthermore, we studied the dynamic susceptibility of these systems, finding that it is possible to control both the position and the number of resonance peaks simply by changing the geometry of the holes. Thus, this work provides useful insights on the behavior of antidot arrays for different geometries, opening routes for the design and improvement of two-dimensional technologies. [ABSTRACT FROM AUTHOR]

We report spin-wave excitations in annular antidot lattice fabricated from 15 nm-thin Ni80Fe20 film. The nanodots of 170 nm diameters are embedded in the 350 nm (diameter) antidot lattice to form the annular antidot lattice, which is arranged in a square lattice with edge-to-edge separation of 120 nm. A strong anisotropy in the spin-wave modes are observed with the change in orientation angle (ϕ) of the in-plane bias magnetic field by using Time-resolved Magneto-optic Kerr microscope. A flattened four-fold rotational symmetry, mode hopping and mode conversion leading to mode quenching for three prominent spin-wave modes are observed in this lattice with the variation of the bias field orientation. Micromagnetic simulations enable us to successfully reproduce the measured evolution of frequencies with the orientation of bias magnetic field, as well as to identify the spatial profiles of the modes. The magnetostatic field analysis, suggest the existence of magnetostatic coupling between the dot and antidot in annular antidot sample. Further local excitations of some selective spin-wave modes using numerical simulations showed the anisotropic spin-wave propagation through the lattice. [ABSTRACT FROM AUTHOR]

In this article we present a new method for construction of exact solutions of the Landau-Lifshitz-Gilbert equation (LLG) for ferromagnetic nanowires. The method is based on the established relationship between the LLG and the nonlinear Schrödinger equation (NLS), and is aimed at resolving an old problem: how to produce multiple-rogue wave solutions of NLS using just the Darboux-type transformations. The solutions of this type—known as P-breathers—have been proven to exist by Dubard and Matveev, but their technique heavily relied on using the solutions of yet another nonlinear equation, the Kadomtsev-Petviashvili I equation (KP-I), and its relationship with NLS. We have shown that in fact one doesn’t have to use KP-I but can instead reach the same results just with NLS solutions, but only if they are dressed via the binary Darboux transformation. In particular, our approach allows us to construct all the Dubard-Matveev P-breathers. Furthermore, the new method can lead to some completely new, previously unknown solutions. One particular solution that we have constructed describes two “positon”-like waves, colliding with each other and in the process producing a new, short-lived rogue wave. We called this unusual solution (in which a rogue wave is begotten after the impact of two solitons) the “impacton”. [ABSTRACT FROM AUTHOR]