Stable Liquid Research Articles

Ruthenium Electrodeposition from Non-Aqueous Electrolytes Containing Divalent Ions

Ruthenium as a metal is characterized by interesting technological and aesthetic properties, which make it an ideal choice for many applications. Ruthenium is dark grey in appearance, it presents a reduced tendency to corrode, low contact resistance and high hardness. When applied in the form of thin films, it can be used in jewels production, protection of electrical contacts, deposition of barrier layers in microelectronics and manufacturing of interconnects in integrated circuits [1].Ruthenium layers can be advantageously deposited exploiting electrodeposition, typically from aqueous sulfamate based electrolytes containing the metal in the form of a complex known as μ-nitridobisaquatetrachlororuthenate [Ru2(μ-N)(H2O)2Cl8]3-. These baths are routinely used at the industrial level and provide good coatings at acceptable cathodic efficiencies. However, ruthenium tends to oxidize in aqueous environment and the resulting deposits can contain impurities or oxides. In addition, the electrodeposition of ruthenium in water-based electrolytes presents difficulties when thick and crack-free coatings are required.In an attempt to solve these limitations, the use of non-aqueous electrolytes for the deposition of ruthenium coatings has been proposed. The substitution of water with alternative solvents can potentially relieve the problem of ruthenium oxidation. Moreover, non-aqueous electrolytes are characterized by wide potential windows, which translate into a reduction in the entity of parasitic hydrogen evolution reactions. Consequently, the properties of the deposit obtained can be potentially improved. In the context of non-aqueous electrolytes, ruthenium has been deposited from water and air stable ionic liquids [2, 3] and from deep eutectic solvents [4].With respect to our previous paper on the deposition of ruthenium [4], where the metal was deposited from the (IV) oxidation state, the present work describes a diametrically different approach. Indeed, we investigate the electrodeposition of ruthenium layers from a non-aqueous electrolyte based on ethylene glycol and containing the metal in its divalent state. The (II) oxidation state is obtained by reducing trivalent RuCl3 with ascorbic acid. A complete physical and electrochemical characterization of the resulting electrolytes is performed, demonstrating the reduction of Ru(III) to Ru(II). The deposition of thin and thick layers is attempted and the resulting coatings are characterized to exclude the possible presence of oxides or other secondary phases. Finally, the possible application of ruthenium layers for electrical contacts protection is evaluated.[1] R. Bernasconi and L. Magagnin, J. Electrochem. Soc. 166(1), D3219-D3225 (2019)[2] O. Raz, G. Cohn, W. Freyland, O. Mann and Y. Ein-Eli, Electrochim. Acta 54, 6042 (2009)[3] O. Mann, W. Freyland, O. Raz and Y. Ein-Eli, Chem. Phys. Lett. 460, 178 (2008)[4] R. Bernasconi, A. Lucotti, L. Nobili and L. Magagnin, J. Electrochem. Soc. 165(13), D620-D627 (2018)

Fluidization-melting characteristics of fly ash from municipal solid waste incineration

Fly ash (FA) from municipal solid waste incineration contains hazardous substances such as dioxins, furans, and heavy metals. Melting FA has proved to be an effective method for reducing volume and mass, while also rendering the waste harmless. However, during the melting process, the addition of a fluxing agent with calorific value is currently necessary to increase melting capacity and reduce energy consumption, which presents a challenge. To tackle this issue, a fluidization-melting technology for a fuel/FA mixture is proposed, wherein a fuel source is employed in the melting process, producing ash that can serve as a fluxing agent. To test this approach, rice husk (RH) was utilized as fuel in a small-scale fluidization-melting test. The objective of this study was to examine the operation parameters of the platform and the characteristics of the resulting product, and to evaluate the harm reduction effect of the slag and its potential for resource utilization. The operating temperature was set at 690 °C in the thermal modification unit and at 1450 °C in the melting furnace, resulting in stable operation and continuous liquid slag discharge. The leaching toxicity of heavy metals in the obtained slag was lower than the standard limit, achieving harmless disposal of FA. However, the resource utilization potential of the obtained slag is limited due to its failure to meet the criteria of vitrified substance and environmental quality requirements. These limitations could be addressed by promoting the combustion of carbon in the melting furnace and accelerating the cooling rate of the slag in the quenching unit.

Ionic Polymer-Metal Composites: From Material Engineering to Flexible Applications.

ConspectusIonic polymer-metal composites (IPMCs) are one kind of artificial muscles that can realize energy conversions in response to external stimulus with merits of lightweight, scalability, quick response, and flexibility and have been treated as an important platform in artificial intelligence, such as bionic robotics, smart sensors, and micro-electromechanical systems. It is well-known that IPMC devices are mainly composed of one electrolyte layer laminated with symmetric electrode layers and realize energy conversion based on ion migration and redistribution inside the devices. However, several critical issues have greatly impeded the practical applications of IPMC devices, including metal electrode cracks, metal-polymer interface detachment, and water loss in the electrolyte. In the past decade, our group and collaborators have made attempts to address the mentioned critical issues with the purpose of accelerating practical applications of IPMC devices. First, in order to address the metal electrode cracks, we have developed various electrode materials to replace the metal electrode material, such as black phosphorus and graphdiyne. These materials display superior electrical and mechanical properties with enhanced material stability without cracking. Second, to address metal-polymer interface detachment, we have designed robust interfaces for IMPC devices with vertical array structures. The as-prepared interfaces present high ionic conductivity with excellent mechanical stability under bending states. As a result, the IPMC devices deliver high working stability exceeding a million cycles under air conditions. Third, in order to avoid water loss in the electrolyte, especially at ambient conditions, we have developed ionogel electrolytes containing highly stable ionic liquids as active ion sources. The ionogel electrolytes effectively prevent water loss in conventional water-containing electrolytes, just like Nafion electrolytes and greatly improve the working stability of IPMC devices. After addressing the key issues of IPMC devices, we finally obtained many high-performing IPMC devices and explored various intelligent applications of them. For instance, we have demonstrated the smart functions of IPMC devices as sensitive strain sensors, such as sign language recognition, handwriting detection, and human muscle monitoring. In addition, we have developed bionic flying robots with a vibration frequency as high as 30 Hz with the aid of high-performance IPMC actuators. A medical catheter based on IPMC actuators has been put forward by our group and can realize multiple degrees of freedom deformation under a low driving voltage of 2.5 V, which presents great potential for application in medical instruments. Lastly, a perspective on critical challenges and future research directions on IPMC materials and devices is highlighted for accelerating practical application.

Polyarylisocyanides Derived from an Alkyne-Pd(II) Catalyst as Robust Alignment Media with Excellent Enantiodiscimination.

The development of chiral alignment media for measuring anisotropic NMR parameters provides an opportunity to determine the absolute configuration of chiral molecules without the need for derivatization. However, chiral alignment media with a high and robust enantiodiscriminating property for a wide range of chiral molecules are still scarce. In this study, we synthesized cholesterol-end-functionalized helical polyisocyanides from a chiral monomer using a cholesterol-based alkyne-Pd(II) initiator. These stereoregular polyisocyanides form stable and weak anisotropic lyotropic liquid crystals (LLCs) in dichloromethane systems, exhibiting highly optical activities in both single left- and right-handed helices. The preparation process of the media was straightforward, and the aligning property of the LLCs could be controlled by adjusting the concentration and temperature. Using the chiral polyisocyanides, we extracted the residual dipolar coupling for an enantiomeric pair of isopinocampheol (IPC), as well as a number of pharmaceutical molecules, demonstrating excellent enantiodiscriminating properties for a broad range of chiral compounds.

Self-Assembled Supported Ionic Liquids.

Separation and reuse of the catalytically active metal complexes are persistent issues in homogeneous catalysis. Supported Ionic Liquid Phase (SILP) catalysts, where the catalytic center is dissolved in a thin film of a stable ionic liquid, deposited on a solid support, present a promising alternative. However, the dissolution of the metal center in the film leaves little control over its position and its activity. We present here four novel, task-specific ionic liquids [FPhn ImH R]I (n=1, 2; R=PEG2 , C12 H25 ), designed to self-assemble on a silica surface without any covalent bonding and offering a metal binding site in a controlled distance to the support. Advanced multinuclear solid-state NMR spectroscopic techniques under Magic Angle Spinning, complemented by molecular dynamics (MD) simulations, allow us to determine their molecular conformation when deposited inside SBA-15 as a model silica support. We provide here conceptual proof for a rational design of ionic liquids self-assembling into thin films, opening an avenue for a second, improved generation of SILP catalysts.

The use of phase change material as an actuator in linkage fabric structures

Linkage fabric structures show potential as assistive technology that can provide support and assistance for individuals with specific mobility and disability needs. The core functionality of these fabrics is the ability to passively and actively control the mechanics of each link producing a structure with variable and adjustable stiffness. Current actuators have shown limited ability to produce active stiffening within a fabric structure without the addition of a continuous energy supply to the structure, therefore, limiting its use as wearable assistive technology. Here, we address the energy supply problem and show the novel use of sodium acetate trihydrate (SAT) in the linkage structures to induce mechanical stiffening through a phase change induced by an electric impulse. We find that a SAT aqueous concentration of 55 wt% is optimum to achieve a stable supercooled liquid (to ambient temperature) and effective electrical nucleation from liquid to solid, which provides robust locking mechanism of individual linkages able to withstand mechanical torsion up to 200 mNm. We demonstrate proof of principle through the integration of SAT into one- and two-dimensional linkage structures and their nearly instantaneous stiffening within each link by enabling electrically controlled actuation.

Mechanical Actuation via Homeomorphic Transformations of Topological Solitons within Polymer Coatings.

Topological solitons are currently under investigation for their exotic properties, especially in nonlinear physics, optics, and material sciences. However, challenges of robust generation and limited stability over time have hindered their practical uses. To address this issue, an approach is developed to form structured arrays of solitons in films of polymerizable liquid crystals. Their complex molecular architecture is preserved by in situ photopolymerization forming a stable liquid crystal network. Most excitingly, their properties are advanced to include responsiveness functions. When thermally actuated, these topological solitons mediate the reconfiguration of surface topographies. Complex shape changes occur depending on the intrinsic complex spatial distribution of the director, which may even lead to full shape inversion and topographical changes as high as ≈40% of the initial thickness. Conversely, the shape changes provide information on the initial director profile, which is consistent with the mathematical model. The soliton-containing polymer coatings are applicable in multiple domains, ranging from tunable optics to haptics, and from shape-coupled sensing systems to temperature-coupled heat management.

Mechanistic study on metastable and stable liquid–liquid phase separation explored by molecular simulation and thermodynamic analysis

Liquid–liquid phase separation (LLPS) has been proven to play a key role in molecular self-assembly both in vivo and in vitro, and it is of great significance for life science and materials science. Comparative elucidation and research are essential for comprehensive understanding of different types of LLPS. Here, citicoline sodium was taken as model molecule to study stable and metastable LLPS. Process analytical technologies (PAT) were applied to characterize the process. Ternary phase diagrams and the solubility parameters of LLPS region were determined and discussed. Moreover, a combination of molecular simulations and spectroscopy was applied to analyze the mechanism of stable and metastable LLPS. Spectroscopy analyses showed that the solute molecules in metastable liquid intermediate were in a metastable state. And the MD simulation results indicated that LLPS was stable when the system was in the solvation-enhanced state, while metastable when the system was in the desolvation state.

Thermodynamically stable ionic liquid microemulsions pioneer pathways for topical delivery and peptide application

Copper peptides (GHK-Cu) are a powerful hair growth promoter with minimal side effects when compared with minoxidil and finasteride; however, challenges in delivering GHK-Cu topically limits their non-invasive applications. Using theoretical calculations and pseudo-ternary phase diagrams, we designed and constructed a thermodynamically stable ionic liquid (IL)-based microemulsion (IL-M), which integrates the high drug solubility of ILs and high skin permeability of microemulsions, thus improving the local delivery of copper peptides by approximately three-fold while retaining their biological function. Experiments in mice validated the effectiveness of our proposed IL-M system. Furthermore, the exact effects of the IL-M system on the expression of growth factors, such as vascular endothelial growth factor, were revealed, and it was found that microemulsion increased the activation of the Wnt/β-catenin signaling pathway, which includes factors involved in hair growth regulation. Overall, the safe and non-invasive IL microemulsion system developed in this study has great potential for the clinical treatment of hair loss.

A numerical study of flow over supersonic projectile under heavy rain

This paper presents a computational fluid dynamics study of morphology and structure dynamics of the flow over a supersonic secant-ogive cylinder boat tail projectile under heavy rain. The discrete phase model is employed to approximate the process of droplet–particle collision with the projectile wall and the formation of a liquid film. The simulation results indicate that at certain angles of attack, rain impact decreases lift coefficient of projectile by as much as 14.9%, as the wall pressure distribution is distinctly reformed. Moreover, the rain condition induces the formation of a liquid film on the front end of the projectile, as the angle of attack increases, the stability of this liquid film gradually improves, while its thickness and coverage rise to the peak values and then decrease. On the projectile’s trailing half, however, the liquid film developed a watery pattern. The collision of liquid droplets causes momentum loss to the projectile, while an unstable liquid film tends to exacerbate aerodynamic performance loss, a stable liquid film would mitigate the performance loss.

Self-standing electrospun Co/Zn@N-doped carbon nanofiber electrode for highly stable liquid and solid-state rechargeable zinc-air batteries and performance evaluated by scanning electrochemical microscopy at various temperatures

Zinc-air batteries (ZABs) as promising energy storage technologies have shown immense advantages of high energy density, abundant zinc reserves, low cost, and high safety. However, the sluggish oxygen reduction reaction (ORR) kinetics at the cathode still limits their overall performances. Herein, we fabricated a self-supported N-doped Co/Zn-carbon nanofiber membrane (Co/Zn@NCF) with superior activity and durability for the ORR. The liquid ZABs based on Co/Zn@NCF catalysts exhibited a cycling life of over 666 h with a charge/discharge voltage difference of 0.64 V and a voltage efficiency of 66 %. The fabricated flexible solid-state ZAB enables it to be stably charged and discharged under different bending angles. Strikingly the temperature-controlled scanning electrochemical microscopy (SECM) was developed to probe the local activity and selectivity of membrane-like Co/Zn@NCF at a submicrometer scale. This study provides an effective way for the development of self-supported catalysts for energy conversion devices and offers the in-operando technique for the analysis of catalysts in various operating temperatures.

Thermal stabilities and decomposition mechanisms under oxygen and nitrogen atmospheres for imidazolium ionic liquids with different cations

Ionic liquids (ILs) are room temperature molten salts, have received extensive attention from the academic community due to their excellent characteristics. In the context of global warming, more and more scholars are looking forward to using ILs as a gas adsorbents, especially ILs containing bis(trifluoromethylsulfonyl)imine (Tf2N). It is well known that the thermal stabilities of ILs are affected by many factors, and the cation type is one of them. In this paper, five imidazole ILs with different functional groups on the side chains of the imidazole rings were selected as the research objects, and their anions were all Tf2N. The thermal decomposition characteristics and thermal effects of the selected samples were determined by thermal gravimetric analyzer (TGA) and differential scanning calorimetry (DSC). The experimental data showed that the most stable ionic liquid was that with the simplest side chain, and the more complex the side chain was, the lower the thermal stability of the sample. In addition, some of their decomposition products were studied with thermogravimetric analyzer coupled with Fourier-transform infrared spectrometry (TG–FTIR). The decomposition mechanisms of the samples did not change under different atmospheres.

Simultaneous quantification of seven B vitamins in human faeces by stable isotope label-based high-performance liquid chromatography-tandem mass spectrometry

B vitamins in the human distal gut are primarily derived from the gut microbiota because daily dietary vitamins are fully absorbed in the small intestine under normal dietary and physiological conditions. Quantitative determination of B vitamins in the distal gut and faecal samples is crucial for understanding the intricate relationship between gut B vitamins, gut microbiota, and host health. In this study, we developed a rapid, robust, and reliable method with a simple extraction procedure for the simultaneous analysis of seven B vitamins in human faeces using high-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (HPLC-ESI-MS/MS) with stable isotope-labelled internal standards. A protein precipitation approach using methanol as the precipitant was employed to extract vitamin B from human faecal samples. Seven B vitamins were adequately separated and quantified within 9 min by HPLC-ESI-MS/MS with a Pursuit PFP column (2.0 ×150 mm, 3.0 µm), including vitamins B1, B2, B3, B5, pyridoxic acid, pyridoxine, and B7. The lower limits of quantification were within the range of 0.1–25 ng mL−1. The intra-day and inter-day precision and accuracy were both within 15 %. The validated method was successfully applied to 55 faecal samples collected from healthy individuals, patients with type 2 diabetes, and obese patients. Compared with healthy controls, obese patients had lower faecal concentrations of vitamins B1 and B3 and pyridoxic acid, whereas patients with type 2 diabetes had lower faecal concentrations of vitamins B1 and B5.

3D-printed sheet jet for stable megahertz liquid sample delivery at X-ray free-electron lasers.

X-ray free-electron lasers (XFELs) can probe chemical and biological reactions as they unfold with unprecedented spatial and temporal resolution. A principal challenge in this pursuit involves the delivery of samples to the X-ray interaction point in such a way that produces data of the highest possible quality and with maximal efficiency. This is hampered by intrinsic constraints posed by the light source and operation within a beamline environment. For liquid samples, the solution typically involves some form of high-speed liquid jet, capable of keeping up with the rate of X-ray pulses. However, conventional jets are not ideal because of radiation-induced explosions of the jet, as well as their cylindrical geometry combined with the X-ray pointing instability of many beamlines which causes the interaction volume to differ for every pulse. This complicates data analysis and contributes to measurement errors. An alternative geometry is a liquid sheet jet which, with its constant thickness over large areas, eliminates the problems related to X-ray pointing. Since liquid sheets can be made very thin, the radiation-induced explosion is reduced, boosting their stability. These are especially attractive for experiments which benefit from small interaction volumes such as fluctuation X-ray scattering and several types of spectroscopy. Although their use has increased for soft X-ray applications in recent years, there has not yet been wide-scale adoption at XFELs. Here, gas-accelerated liquid sheet jet sample injection is demonstrated at the European XFEL SPB/SFX nano focus beamline. Its performance relative to a conventional liquid jet is evaluated and superior performance across several key factors has been found. This includes a thickness profile ranging from hundreds of nanometres to 60 nm, a fourfold increase in background stability and favorable radiation-induced explosion dynamics at high repetition rates up to 1.13 MHz. Its minute thickness also suggests that ultrafast single-particle solution scattering is a possibility.

Quantification of Resveratrol in Peanut Oils Using Stable Isotope Dilution Ultra-high Performance Liquid Chromatography-Mass Spectrometry

Quantification of Resveratrol in Peanut Oils Using Stable Isotope Dilution Ultra-high Performance Liquid Chromatography-Mass Spectrometry

Highly flexible and stable green perovskite light-emitting diodes based on IL-modified PEDOT:PSS film

Flexible light-emitting diodes (LEDs) are highly sought-after for various applications, such as wearable medical devices, decorative lighting, and flexible displays. Perovskite-based LEDs, due to their low cost, ease of fabrication, and high color purity, have attracted significant attention as promising candidates for modern display technology. However, a primary challenge remains in selecting a bottom anode that provides both high electrical conductivity and optical transmittance while maintaining mechanical robustness to endure rigorous bending. To address this issue, a highly flexible and stable ionic liquid (IL)-modified poly(3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS) bottom anode was developed for high-performance flexible perovskite LEDs (PeLEDs). The addition of 1-ethyl-3-methylimidazolium tetracyanoborate (EMIM TCB) IL initiates a depth-dependent rearrangement of the PEDOT and PSS moieties within the PEDOT:PSS film and improves its conductivity by orders of magnitude. Additionally, the IL increases the work function of the PEDOT:PSS layer, leading to a reduced barrier for hole injection. The fabricated flexible green PeLEDs exhibited pure green emission at 520 nm with a maximum external quantum efficiency (EQE) of 11.6% and maximum luminance of 25566.8 cd/m2. Remarkably, the device retained 85% of its initial luminance after 5000 bending cycles at a 5 mm bending radius.

Effects of ice content on compression characteristics of frozen sandstone by in-situ NMR technology

In cold regions, the freezing of pore water in rock affects the mechanical behavior of the rock. This paper studied the ice content of frozen sandstone at different temperatures and its effects on the mechanical properties of sandstone. First, the progressive freezing treatment (from 25.0 to − 30.0 °C) and in-situ nuclear magnetic resonance test were conducted to study the evolution of the ice content of sandstone with temperature. This evolution was quantitatively described by the frozen ratio defined as the percentage of the mass of ice and the total mass of water. Then, the mechanical properties of frozen sandstone at different temperatures (25.0 °C, 0.0 °C, − 5.0 °C, − 10.0 °C, − 20.0 °C and − 30.0 °C, respectively) were tested, such as P-wave velocity, uniaxial compressive strength (UCS), peak strain and elastic modulus. Finally, the effects of the frozen ratio on these properties were discussed. The results show that the pore water in sandstone shows three stages as the temperature decreases: stable liquid (from 25.0 to 0.0 °C), sharp phase transition (from 0.0 to − 2.5 °C) and slow phase transition (from − 2.5 to − 30.0 °C). Especially, the capillary and bulk water in sandstone is almost completely frozen in the sharp phase transition stage. As the temperature decreases, the frozen ratio first remains constant, then increases rapidly and finally increases slowly. Moreover, as the frozen ratio increases, the P-wave velocity, UCS and peak strain increase while the elastic modulus decreases. Interestingly, the compressive failure mode of sandstone changes from brittle to ductile as the frozen ratio increases.

Origin of hot cracking formation and suppression method in laser additive manufactured nickel-based superalloys

Although laser additive manufacturing is a promising technique for fabricating nickel-based single crystal superalloy components, reducing hot cracking during the deposition is still a challenge. In this study, the cracking susceptibility and microstructures with different substrates are investigated. Results show that samples exhibit much lower cracking susceptibility when using the directional solidified substrates than the cast polycrystalline substrates. Hot cracking is attributed to a stable liquid film dependent on the misorientation angle. Besides, liquation cracking first occurs in the substrate and could propagate by extension into solidification cracks along the high angle grain boundaries. Based on these findings, a crack-free nickel-based superalloy with a polycrystalline substrate is successfully prepared using a continuous scanning strategy.

Thermal management of high flux electronics using film evaporation with an enhanced fluid delivery system (FEEDS)

The increasing power densities of electronic devices due to more compact package requirements make their thermal management a major challenge. Adequate cooling of these devices is required to increase their lifespan and maintain operational capabilities. Over the past couple of decades, microchannel heat sinks, among other solutions, have been implemented to dissipate high heat fluxes under operational parameters of practical significance. Furthermore, convective heat transfer coefficients have been increased by using a two-phase flow and by reducing the hydraulic diameters of the channels. However, this incurs an increase in pressure drop and pumping power. A novel cooling technique, film evaporation with an enhanced fluid delivery system (FEEDS), has been demonstrated to simultaneously enhance the heat transfer coefficient while minimizing the increased pressure drop and pumping power requirements. The FEEDS cooler is a manifold-microchannel system in which an array of manifolds is positioned perpendicularly on a system of parallel microchannels. In the present work, two FEEDS coolers were designed and developed to manage high heat fluxes of electronic components. The geometrical parameters of the manifolds were varied to investigate the effect of manifold parameters on thermal and hydrodynamic performances. Both single-phase and two-phase tests were performed with R-245fa refrigerant as the working fluid at different mass fluxes, and heat transfer and pressure drop performances were measured. Heat fluxes in excess of 1 kW/cm2 with a surface superheat of 38 °C and with a low-pressure drop penalty were achieved. Additionally, this FEEDS cooler showed a relatively constant heat transfer coefficient even after the optimal vapor quality was exceeded, indicating a stable liquid film.

On the origin of cracking in laser powder bed fusion processed LaCe(Fe,Mn,Si)13, and the impact of post-processing

LaCe(Fe,Mn,Si)13 magnetocaloric material printed by laser powder bed fusion (LPBF) has a huge potential for magnetic refrigeration. However, high crack and defect susceptibility in LPBF processing remains a limitation of its application. This study optimised the LPBF process parameters for optimally dense blocks. The volumetric energy density condition, EV = 250 J/mm3, showed the lowest crack density and porosity fraction. The behaviour and mechanism of different cracks and defects were revealed. The lower energy density parameter sets, caused by higher scanning speeds and hatch spacing, lead to the formation of lack-of-fusions. The hot cracking observed was attributed to stress concentration and a stable liquid film. The solid-state cracks observed were expected in the microstructure of the as-fabricated (AF) sample due to the poor toughness of the La/Ce/Si-rich phases. Thermal heat treatment and quenching increased the magnetocaloric effect (MCE) of the AF sample. The maximum magnetic entropy change (∆Smax) of the heat-treated sample was − 3.68 Jkg−1K−1 at 294 K, when applied to a 1 T field. The Curie temperature (Tc) (298 K when applied 0.01 T field) and superior MCE make the material an ideal choice for realising room-temperature magnetic refrigeration.