Endothermic reaction at room temperature enabled by deep-ultraviolet plasmons.

Metallic nanoparticles have been used to harvest energy from a light source and transfer it to adsorbed gas molecules, which results in a reduced chemical reaction temperature. However, most reported reactions, such as ethylene epoxidation, ammonia decomposition and H-D bond formation are exothermic, and only H-D bond formation has been achieved at room temperature. These reactions require low activation energies (<2 eV), which are readily attained using visible-frequency localized surface plasmons (from ~1.

Microstructural Analysis and Mechanical Properties of TiMoZrTaSi Alloys as Biomaterials.

TiMoZrTaSi alloys appertain to a new generation of metallic biomaterials, labeled high-entropy alloys, that assure both biocompatibility as well as improved mechanical properties required by further medical applications. This paper presents the use of nondestructive evaluation techniques for new type of alloys, TiMoZrTaSi, with x = 0; 0.5; 0.

Probing the Optical Properties and Strain-Tuning of Ultrathin MoW Te.

Ultrathin transition metal dichalcogenides (TMDCs) have recently been extensively investigated to understand their electronic and optical properties. Here we study ultrathin MoWTe, a semiconducting alloy of MoTe, using Raman, photoluminescence (PL), and optical absorption spectroscopy. MoWTe transitions from an indirect to a direct optical band gap in the limit of monolayer thickness, exhibiting an optical gap of 1.

The structural phases and vibrational properties of MoWTe alloys.

The structural polymorphism in transition metal dichalcogenides (TMDs) provides exciting opportunities for developing advanced electronics. For example, MoTe crystallizes in the 2H semiconducting phase at ambient temperature and pressure, but transitions into the 1T' semimetallic phase at high temperatures. Alloying MoTe with WTe reduces the energy barrier between these two phases, while also allowing access to the T Weyl semimetal phase.

Characterization of Few-Layer 1T' MoTe by Polarization-Resolved Second Harmonic Generation and Raman Scattering.

We study the crystal symmetry of few-layer 1T' MoTe using the polarization dependence of the second harmonic generation (SHG) and Raman scattering. Bulk 1T' MoTe is known to be inversion symmetric; however, we find that the inversion symmetry is broken for finite crystals with even numbers of layers, resulting in strong SHG comparable to other transition-metal dichalcogenides. Group theory analysis of the polarization dependence of the Raman signals allows for the definitive assignment of all the Raman modes in 1T' MoTe and clears up a discrepancy in the literature.

An Electromagnetic Sensor with a Metamaterial Lens for Nondestructive Evaluation of Composite Materials.

This paper proposes the study and implementation of a sensor with a metamaterial (MM) lens in electromagnetic nondestructive evaluation (eNDE). Thus, the use of a new type of MM, named Conical Swiss Rolls (CSR) has been proposed. These structures can serve as electromagnetic flux concentrators in the radiofrequency range.

Metallic strip gratings in the sub-subwavelength regime.

Metallic strip gratings (MSG) have different applications, ranging from printed circuits to filters in microwave domains. When they are under the influence of an electromagnetic field, evanescent and/or abnormal modes appear in the region between the traces, their utilization leading to the development of new electromagnetic nondestructive evaluation methods. This paper studies the behavior of MSGs in the sub-subwavelength regime when they are excited with TE(z) or TM(z) polarized plane waves and the slits are filled with different dielectrics.

DFT study of the structures and energetics of 98-atom AuPd clusters.

The energetics, structures and segregation of 98-atom AuPd nanoclusters are investigated using a genetic algorithm global optimization technique with the Gupta empirical potential (comparing three different potential parameterisations) followed by local minimizations using Density Functional Theory (DFT) calculations. A shell optimization program algorithm is employed in order to study the energetics of the highly symmetric Leary Tetrahedron (LT) structure and optimization of the chemical ordering of a number of structural motifs is carried out using the Basin Hopping Monte Carlo approach. Although one of the empirical potentials is found to favour the LT structure, it is shown that Marks Decahedral and mixed FCC-HCP motifs are lowest in energy at the DFT level.