Local chemical order enables an ultrastrong and ductile high-entropy alloy in a cryogenic environment.

Owing to superior strength-ductility combination and great potential for applications in extreme conditions, high-entropy alloys (HEAs) with the face-centered cubic (FCC) structure have drawn enormous attention. However, the FCC structure limits yield strength and makes the alloys unable to meet ever-increasing demands for exploring the universe. Here, we report a strategy to obtain FCC materials with outstanding mechanical properties in both ambient and cryogenic environments, via exploiting dynamic development of the interstitial-driven local chemical order (LCO).

Giant Elastocaloric Effect and Improved Cyclic Stability in a Directionally Solidified (NiMnTi)B Alloy.

Superelastic shape memory alloys with an integration of large elastocaloric response and good cyclability are crucially demanded for the advancement of solid-state elastocaloric cooling technology. In this study, we demonstrate a giant elastocaloric effect with improved cyclic stability in a <001> textured polycrystalline (NiMnTi)B alloy developed through directional solidification. It is shown that large adiabatic temperature variation (|Δ|) values more than 15 K are obtained across the temperature range from 283 K to 373 K.

Layer-by-layer phase transformation in TiO revealed by machine-learning molecular dynamics simulations.

Reconstructive phase transitions involving breaking and reconstruction of primary chemical bonds are ubiquitous and important for many technological applications. In contrast to displacive phase transitions, the dynamics of reconstructive phase transitions are usually slow due to the large energy barrier. Nevertheless, the reconstructive phase transformation from β- to λ-TiO exhibits an ultrafast and reversible behavior.

Realization of Large Low-Stress Elastocaloric Effect in TiZrNbAl Alloy.

Seeking novel high-performance elastocaloric materials with low critical stress plays a crucial role in advancing the development of elastocaloric refrigeration technology. Here, as a first attempt, the elastocaloric effect of TiZrNbAl shape memory alloy at both room temperature and finite temperatures ranging from 245 K to 405 K, is studied systematically. Composition optimization shows that Ti-19Zr-14Nb-1Al (at.

Impact of Mn Alloying on Phase Stabilities, Magnetic Properties and Electronic Structures in Fe.

Impacts of Mn alloying on lattice stabilities, magnetic properties, electronic structures of the bcc and fcc phases and the fcc→bcc phase transition in Fe16-xMnx (x = 0, 1 and 2) alloys are studied by first-principles calculations. Results show that the doped Mn atom prefers ferromagnetic and antiferromagnetic interaction with the host Fe atoms in the bcc and fcc phases, respectively. In these two phases, the magnetic moment of Mn is smaller and larger than Fe, respectively.

Achieving Excellent Strength-Ductility Balance in Single-Phase CoCrNiV Multi-Principal Element Alloy.

CoCrNi alloys exhibit excellent strength and ductility. In this work, the CoCrNiV multi-principal alloy with single-phase fine grained (FG) structure was prepared by rolling and heat treatment. The characteristics of deformation microstructures and mechanical properties were systematically investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM).

Flatband λ-TiO towards extraordinary solar steam generation.

Solar steam interfacial evaporation represents a promising strategy for seawater desalination and wastewater purification owing to its environmentally friendly character. To improve the solar-to-steam generation, most previous efforts have focused on effectively harvesting solar energy over the full solar spectrum. However, the importance of tuning joint densities of states in enhancing solar absorption of photothermal materials is less emphasized.

Effects of V Addition on the Deformation Mechanism and Mechanical Properties of Non-Equiatomic CoCrNi Medium-Entropy Alloys.

Equiatomic CoCrNi medium-entropy alloys exhibit superior strength and ductility. In this work, a non-equiatomic CoCrNi alloy with low stacking fault energy was designed, and different fractions of V were added to control the stacking fault energy and lattice distortion. Mechanical properties were evaluated by tensile tests, and deformation microstructures were characterized by transmission electron microscope (TEM).

Influence of the Sputtering Temperature on Reflectivity and Electrical Properties of ITO/AgIn/ITO Composite Films for High-Reflectivity Anodes.

In this paper, indium tin oxide/silver indium/indium tin oxide (ITO/AgIn/ITO) composite films were deposited on glass substrates by magnetron sputtering. The effects of the sputtering temperature on the optical and electrical properties of the composite films were systematically investigated. The ITO/AgIn/ITO composite films deposited at sputtering temperatures of 25 °C and 100 °C demonstrated a high reflectivity of 95.

Large Cryogenic Magnetostriction Induced by Hydrostatic Pressure in MnCoNiSi Alloy.

Giant magnetostriction could be achieved in MnCoSi-based alloys due to the magneto-elastic coupling accompanied by the meta-magnetic transition. In the present work, the effects of hydrostatic pressure on magnetostrictive behavior in MnCoNiSi alloy have been investigated. The saturation magnetostriction (at 30,000 Oe) could be enhanced from 577 ppm to 5034 ppm by the hydrostatic pressure of 3.

Correction: First-principles insights into hydrogen trapping in interstitial-vacancy complexes in vanadium carbide.

Correction for 'First-principles insights into hydrogen trapping in interstitial-vacancy complexes in vanadium carbide' by Shuai Tang , , 2022, DOI: https://doi.org/10.1039/d2cp02425j.

First-principles insights into hydrogen trapping in interstitial-vacancy complexes in vanadium carbide.

Hydrogen trapping is a key factor in designing advanced vanadium alloys and steels, where the influence of carbon vacancies is still elusive. Herein we have investigated the effect of carbon vacancies on the hydrogen trapping of defect-complexes in vanadium carbide using first-principles calculations. When a carbon vacancy is present, the second nearest neighboring trigonal interstitial is a stable hydrogen trapping site.

Enhanced Magnetostrain in a <0 0 1>A-Textured Ni44.5Co4.9Mn37.5In13.1 Alloy through Superelastic Training.

Large magnetostrain can be demonstrated in Ni-Mn-X (X = In, Sn, Sb) meta-magnetic shape memory alloys by resuming the predeformed martensite through magnetic-field-induced reverse martensitic transformation. However, owing to the constraint from the self-accommodated microstructure and randomly distributed crystallographic orientation, spontaneous magnetostrain without predeformation in polycrystalline alloys remains low. Here, by combining microstructure texturing and superelastic training, enhanced spontaneous magnetostrain was achieved in a directionally solidified Ni44.

Crystallography and Microstructure of 7M Martensite in Ni-Mn-Ga Thin Films Epitaxially Grown on (1 1 2¯ 0)-Oriented AlO Substrate.

Epitaxial Ni-Mn-Ga thin films have been extensively investigated, due to their potential applications in magnetic micro-electro-mechanical systems. It has been proposed that the martensitic phase in the <1 1 0>A-oriented film is much more stable than that in the <1 0 0>A-oriented film. Nevertheless, the magnetic properties, microstructural features, and crystal structures of martensite in such films have not been fully revealed.

Giant Elastocaloric Effect in Ni-Mn-Ga-Based Alloys Boosted by a Large Lattice Volume Change upon the Martensitic Transformation.

High-performance elastocaloric materials are highly sought in developing energy-efficient and environmentally friendly solid-state elastocaloric refrigeration. Here, we present an effective strategy to achieve a giant elastocaloric response by enlarging the lattice volume change Δ/ upon the martensitic transformation. Using the NiMn binary alloy as the prototype, a large transformation entropy change Δ can be tailored in the vicinity of room temperature by simultaneously doping Cu and Ga.

Large Low-Field Reversible Magnetocaloric Effect in Itinerant-Electron HfTaFe Alloys.

First-order isostructural magnetoelastic transition with large magnetization difference and controllable thermal hysteresis are highly desirable in the development of high-performance magnetocaloric materials used for energy-efficient and environmental-friendly magnetic refrigeration. Here, we demonstrate large magnetocaloric effect covering the temperature range from 325 K to 245 K in Laves phase HfTaFe ( = 0.13, 0.

Magnetic field-induced magnetostructural transition and huge tensile superelasticity in an oligocrystalline Ni-Cu-Co-Mn-In microwire.

Meta-magnetic shape-memory alloys combine ferroelastic order with ferromagnetic order and exhibit attractive multifunctional properties, but they are extremely brittle, showing hardly any tensile deformability, which impedes their practical application. Here, for the first time, an Ni-Cu-Co-Mn-In microwire has been developed that simultaneously exhibits a magnetic field-induced first-order meta-magnetic phase transition and huge tensile superelasticity. A temperature-dependent synchrotron high-energy X-ray diffraction investigation reveals that the martensite of this NiCuCoMnIn microwire shows a monoclinic six-layered modulated structure and the austenite shows a cubic structure.