LAW , Jia Yan

The magnetocaloric effect (MCE) is a phenomenon where varying magnetic fields cause temperature changes in magnetic materials, primarily near their thermomagnetic phase transitions. Its first observation was the induced temperature change of 0.7 K (for 1.5 T at 630 K) in a nickel sample near its thermomagnetic phase transition, but the heart of...

The search for high-performance functional alloys with improved service life and reliability entails the optimization of their mechanical properties. Recently, the high-entropy alloy (HEA) design concept has found new alloys with excellent mechanical properties. It utilizes multiprincipal elements to yield high configurational entropy of...

High-entropy alloys (HEAs) have become a topic of high research interest due to the excellent mechanical properties that can be found in this new type of materials. However, their functional properties are usually modest when compared to conventional materials. The discovery of high-entropy alloys with an optimal combination of mechanical and...

A procedure has been developed to directly measure the adiabatic temperature change of amorphous melt-spun Fe-based ribbons displaying attractive room temperature magnetocaloric properties. Polycrystalline Gd ribbons are used as a reference material to compensate for the contribution of the sample holder to the experimental values. Fe78B12Cr8Ce...

The influence of annealing temperature and crystallization on the magnetocaloric effect (MCE) of Fe-B-Cr-Gd partially crystalline alloys was studied. Although the alloys exhibited dissimilar devitrification behavior, all the alloys exhibited MCE behavior consistent with a phenomenological universal curve and theoretical power law expressions of...

The magnetic entropy change (ΔSM), temperature of peak ΔSM (Tpk) and refrigerant capacity (RC) in Fe(RE)80B12Cr8 (RE = La, Ce, or Gd) alloys were studied. Increasing La, Ce, and Gd content led to relatively constant, decrease, and increase in Tpk, respectively. Both the phenomenologically constructed universal curve for ΔSM and field dependence...

The search for high-entropy alloys (HEAs), a new class of materials, with high magnetocaloric perfor- mance can address the open question about their potential in functional applications. HEAs exist in a vast compositional space but magnetocaloric HEAs typically exhibit modest magnetocaloric response as they undergo second-order magnetic phase...

Magnetocaloric refrigeration has remained a promising alternative to conventional refrigeration for the last few decades. The delay in reaching the market is significantly based on materials' related issues, such as hysteresis/reversibility, mechanical stability, or formability. This perspective paper shows the current trends in magnetocaloric...

The expected energy transition to hydrogen gas as a greener energy vector has revived the interest in magnetic refrigeration at the cryogenic range, specifically between 20 and 80 K, with the vision to develop a new generation of hydrogen gas liquefiers. From the materials science point of view, the search for magnetocaloric materials...

RENiX2 compounds, where RE = rare-earth element and X = p-block element, have been highly regarded for cryogenic magnetocaloric applications. Depending on the elements, they can crystallize in CeNiSi2-type, NdNiGa2-type, or MgCuAl2-type crystal structures, showing different types of magnetic ordering and thus affect their magnetic properties....

In most cases, substitution studies that aim to optimize magnetic properties are performed at the magnetic atomic site. However, in the case of MnB, magnetic substitutions at the Mn site significantly decrease the once promising magnetocaloric and magnetic properties. This study employs computationally directed search to optimize the...

An efficient magnetocaloric refrigerant must have certain characteristics such as a sharp transition near the desired working temperature, a large cyclic magnetocaloric response, and the use of raw materials with reduced costs and low environmental consequences. In this sense, this work focuses on a series of rare-earth- and Co-free...

The design of functional composite filaments for fused filament fabrication requires a suitable polymer composition, functionality of particles, uniform distribution of fillers throughout the filament, and ade- quate printability. Uniform distribution at predictable concentrations is achieved by designing polymeric capsules containing the...

One important issue associated to magnetocaloric materials that hinders its technological application is the poor processability and structural integrity of those with the highest performance, usually intermetallics undergoing first-order magnetic phase transitions. Additionally, the performance of these magnetocaloric materials highly depends...

Additive manufacturing could be an excellent way of shaping magnetocaloric heat exchangers in magnetic refrigerators. However, the metal additive manufacturing techniques present the serious limitation that the melting of a magnetocaloric material can cause its transformation and the loss of functionality. Fused deposition modeling using...

It has been found that GdBa1-xSrxCo2O6-δ can exhibit consecutive magnetic transitions: antiferromagnetic-ferromagnetic (AFM-FM) transition followed by ferromagnetic-paramagnetic transition (FM-PM), which give rise to a coexistence of inverse and conventional magnetocaloric effect (MCE), respectively. In the pristine compound (x = 0), its AFM-FM...

Cryogenic magnetic refrigeration is a highly efficient and environmentally friendly technique for gas liquefaction. However, refrigerant materials undergoing large magnetocaloric response at the interesting cryogenic range are dominated by critical elements (mainly rare-earth elements) which impedes practical applicability of such refrigeration...

Through designing the composition and processing approach, the non-equiatomic (Gd36Tb20Co20Al24)100-xFex (x = 0, 1, 2 and 3 at.%) high-entropy-metallic-glass (HE-MG) alloy microwires were successfully fabricated by melt-extraction technique. The microstructure and magnetocaloric properties of the microwires were systematically investigated. The...

All-d-metal Ni(Co)-Mn-Ti Heusler alloys show high magnetocaloric/barocaloric effects ascribed to the occurrence of a martensitic transformation together with excellent mechanical properties. However, high magnetic fields are needed to fully drive the transformation and to obtain their maximum responses. To further tune the martensitic...

Successful 3D printing by material extrusion of functional parts for new devices requires high quality filaments. Uniform homogeneity and good dispersion of particles embedded in filaments typically takes several cycles of extrusion or well-prepared feedstock by injection molding, industrial kneaders or twin-screw compounding. These methods...

The determination of the magnetocaloric magnitudes (specific magnetic entropy change, Δs M, and adiabatic temperature change, ΔT ad) from heat capacity (c H) measurements requires measurements performed at very low temperatures (∼0 K) or data extrapolation when the low temperature range is unavailable. In this work we analyze the influence on...

In this paper we report an experimental study of structural, magnetic, and mechanical properties of quaternary Heusler alloys Co2−x Yx FeSi (Y = Co, Fe, Mn, Cr, V, Ti, or Sc, 0 x 1) and the experimental findings are supported by ab initio electronic structure calculations. The alloys were synthesized using an arc-melting technique. Single...

In the present work, using Heusler Ni49+xMn36-xIn15 (with x = 0 and 0.5) alloys, it is shown that the choice of the appropriate measurement protocol (erasing the prior state of the sample in between experiments) in DTad first shot characterization is crucial for obtaining reliable results. Unlike indirect measurements, for which incorrect...