Fe 3d Orbitals Research Articles

Seeding Janus Zn-Fe Diatomic Pairs on a Hollow Nanobox for Potent Catalytic Therapy.

Dual atomic nanozymes (DAzymes) are promising for applications in the field of tumor catalytic therapy. Here, integrating with ultrasmall Fe5C2 nanoclusters, asymmetric coordination featuring Janus Zn-Fe dual-atom sites with an O2N2-Fe-Zn-N4 moiety embedded in a carbon vacancy-engineered hollow nanobox (Janus ZnFe DAs-Fe5C2) was elaborately developed. Theoretical calculation revealed that the synergistic effects of Zn centers acting as both adsorption and active sites, oxygen-heteroatom doping, carbon vacancy, and Fe5C2 nanoclusters jointly downshifted the d-band center of Fe 3d orbitals, optimizing the desorption behaviors of intermediates *OH, thereby significantly promoting catalytic activity. Upon 1064 nm laser irradiation, Janus ZnFe DAs-Fe5C2 with superior photothermal conversion efficiency (η = 62.5%) showed thermal-augmented catalytic therapy. Fascinatingly, Janus ZnFe DAs-Fe5C2 with multienzymatic properties can suppress the expression of glutathione peroxidase 4 and accelerate the accumulation of lipid peroxides, through which ferroptosis is triggered. Overall, tannin-involved asymmetric Janus ZnFe DAs-Fe5C2 will inspire more inventions of biodegradable DAzymes for tumor therapy application.

Thermoelectric Properties of a Light Compound Fe2S2: the Role of Electron Correlation Strengthened Spin-Orbital Coupling.

Spin-orbit coupling (SOC) induced nontrivial bandgap and complex Fermi surface has been considered to be profitable for thermoelectrics, which, however, is generally appreciable only in heavy elements, thereby detrimental to practical application. In this study, the SOC-driven extraordinary thermoelectric performance in a light 2D material Fe₂S₂ is demonstrated via first-principles calculations. The abnormally strong SOC, induced by electron correlation through 3d orbitals polarization, significantly renormalizes the band structures, which opens the bandgap via Fe 3d orbitals inversion, exposes the second conduction valley with weak electron-phonon coupling, and aligns the energy of Fe 3d and S 3p orbitals with divergent momentum in valence band. Such topological band renormalization triggers improvement of both p- and n-type power factors by more than 200%. Combining with the low lattice thermal conductivity caused by lone pair electrons and intense high-order phonon scattering, the peak zT can reach 1.6 and 1.8 for p- and n-type Fe₂S₂ at 400 K, respectively. This work unravels the mechanism of SOC-provoked high zT in electron correlation systems, which inspires the development of high-performance thermoelectric materials without heavy and scarce elements.

Untangling the role of single-atom substitution on the improvement of the hydrogen evolution reaction of Y2NS2 MXene in acidic media.

The production of hydrogen (H2) fuel through electrocatalysis is emerging as a sustainable alternative to conventional and environmentally harmful energy sources. However, the discovery of cost-effective and efficient materials for this purpose remains a significant challenge. In this study, we explore the potential of the transition-metal-substituted Y2NS2 MXene as a promising candidate for hydrogen production through the hydrogen evolution reaction (HER). Using density functional theory (DFT) calculations, we first analyzed the Pourbaix diagram, and dissolution potential which showed the stability and resistance to corrosion of the sulfur termination. Later, we address the kinetic limitations of HER on bare Y2NS2 by introducing single-atom substitutions of Y atoms with 3d transition metals. Nine distinct structures were evaluated, revealing that Fe-substituted Y2NS2 exhibits the highest HER activity under acidic conditions, as indicated by volcano plot analyses. Further investigation of the bonding characteristics and electronic density of states highlights the crucial role of Fe d-orbitals and the weak interactions at the sulfur-terminated surface in enhancing the HER efficiency. These findings provide insights into the design of advanced, cost-effective materials for HER catalysis, paving the way for their application as efficient electrochemical catalysts across a wide pH range.

Engineering skyrmion from spin spiral in transition metal multilayers.

Skyrmions having topologically protected field configurations with particle-like properties play an important role in various fields of science. Our present study focus on the generation of skyrmion from spin spiral in the magnetic multilayers of 4d/Fe/Ir(111) with 4d = Y, Zr, Nb, Mo, Ru, Rh. Here we investigate the impact of 4d transition metals on the isotropic Heisenberg exchanges and anti-symmetric Dzyaloshinskii-Moriya interactions originating from the broken inversion symmetry at the interface of 4d/Fe/Ir(111) multilayers. We find a strong exchange frustration due to the hybridization of the Fe-3d layer with both 4d and Ir-5d layers which modifies due to band filling effects of the 4d transition metals. We strengthen the analysis of exchange frustration by shedding light on the orbital decomposition of isotropic exchange interactions of Fe-3d orbitals. Our spin dynamics and Monte Carlo simulations indicate that the magnetic ground state of 4d/Fe/Ir(111) transition multilayers is a spin spiral in theab-plane with a period of 1 to 2.5 nm generated by magnetic moments of Fe atoms and propagating along thea-direction. The spiral wavelengths in Y/Fe/Ir(111) are much larger compared to Rh/Fe/Ir(111). In order to manipulate the skyrmion phase in 4d/Fe/Ir(111), we investigate the magnetic ground state of 4d/Fe/Ir(111) transition multilayers with different external magnetic field. An increasing external magnetic field of ∼12 T is responsible for deforming the spin spiral into a isolated skyrmion which flips into skyrmion lattice phase around ∼18 T in Rh/Fe/Ir(111). Our study predict that the stability of magnetic skyrmion phase in Rh/Fe/Ir(111) against thermal fluctuations is upto temperatureT⩽90 K.

Efficient generation of Fe(IV) = O for water purification in periodate activation process: Reducing Fe orbital occupation and expanding electron transfer channel

The rapid generation of high-valent iron species (Fe(IV) = O) in AOPs has become a challenge for the removal of organic pollutants due to the high electron occupancy in the Fe 3d orbitals and low electron transfer efficiency. Herein, BN modified CuFe2O4 catalysts were constructed by in situ growth of CuFe2O4 nanoparticles on ultrathin BN nanosheets for periodate (PI) catalysis. Especially, the formed Fe-N interface sites not only reduce the electron occupation in the Fe 3d orbitals, but also expand the electronic transfer pathway, thus transforming the oxidation mechanism from one electron process to two electron process for facilitating the Fe(IV) = O and 1O2 generation in the CuFe2O4/BN/PI system. The bimetallic redox cycle between Fe and Cu realizes the accelerated conversion of Fe(III) to Fe(II), promoting the continuous and fast conversion of Fe(II) to Fe(IV) = O via two electron process. As a result, the developed CuFe2O4/BN/PI system exhibits excellent degradation efficiency for oxytetracycline (OTC), achieving 91.02 % OTC removal within 60 min, and maintains relatively high remove efficiency even under different water quality conditions. This research provides a new insight into the evolution of Fe(IV) = O and the deep mechanism of PI activation.

Reconfiguring FeN4 sites through axial Fe2O3 clusters to enhance d-orbital electronic delocalization for improved oxygen reduction reaction

Effectively controlling the electronic configuration of metal sites within single-atom catalysts (SACs) is essential for improving their oxygen reduction reaction (ORR) performance. Here, we construct hybrid catalysts featuring Fe single atoms and Fe2O3 clusters (Fe SACs/Fe2O3@NHPC) to realize highly efficient ORR. Specifically, the Fe SACs/Fe2O3@NHPC delivers a remarkable half-wave potential (E1/2) of 0.893 V and endures 30,000 cycles with only 12 mV E1/2 loss in alkaline media. Liquid zinc–air batteries (ZABs) utilizing Fe SACs/Fe2O3@NHPC output a power density of 192.7 mW cm−2 and demonstrate rechargeability over 370 h without noticeable voltage degradation. Furthermore, theoretical calculations indicate that the axially coordinated Fe2O3 clusters significantly promote electronic delocalization in the 3d orbitals of the Fe sites. This electronic structure regulation strategy optimizes the hybridization between Fe-3d orbitals and O-2p orbitals, thereby facilitating the *OH dissociation process. This research not only provides intensive insight into the synergistic interactions and complementary effects between single-atom sites and clusters in hybrid catalysts but also lays the groundwork for designing SACs.

Confined pyrolysis synthesis of N-doped carbon-supported FePr nanoparticles for efficient oxygen reduction based on 3d–4f orbital coupling

To meet the growing demand for new energy storage and conversion technologies, there is an urgent need to prepare highly efficient, economical and durable oxygen reduction catalysts that can replace those based on precious. Herein, N-doped porous carbon supported FePr nanoparticles (FePr/NC) were prepared by confined adsorption and pyrolysis. The characterizations and electrocatalytic properties of the FePr/NC were investigated in details. The prepared FePr/NC catalyst showed excellent oxygen reduction reaction (ORR) catalytic performance with a half-wave potential (E1/2) of 0.87 V in a 0.1 M KOH solution, outperforming commercial Pt/C catalyst (E1/2 = 0.82 V) under the identical conditions. Besides, its onset potential (Eonset) was up to 1.002 V, exceeding the Pt/C (Eonset = 0.92 V). Moreover, the E1/2 only exhibited a negative shift of 7 mV after 2000 cycles, reflecting its significant stability. To understand their exceptional preference for the ORR, the electronic structure of Fe influenced by the doped Pr and the synergistic effect of the FePr nanoparticles with N-doped carbon were investigated. The coupling of Fe's 3d orbitals with Pr's 4 f orbitals in the FePr significantly enhanced the electrocatalytic activity. This work provides a promising strategy for preparation of high-quality transition metal-based carbon catalysts for green energy devices.

Highly efficient magnesium ferrite/graphene nano-heterostructure for visible-light photocatalytic applications: Experimental and first-principles DFT studies

In this research study, the electronic structure of magnesium ferrite/graphene (MFO/Gr) nano-heterostructure for photocatalytic application was studied. The MFO nanoparticles with a median size of 85 nm were composited with Gr sheets using a photo-assisted reduction process. The XRD and SAED results, respectively, showed the spinal crystalline structure of MFO and the hexagonal structure of Gr in MFO/Gr nanocomposite. The XPS results revealed that the orbitals of MFO and Gr atoms interacted with each other, implying a Van der Waals heterojunction nanocomposite. The optical characteristics using UV–Vis diffuse reflectance spectrophotometry (UV–Vis DRS) and photoluminescence (PL) spectra demonstrated a lowering of MFO band gap from 2.05 to 1.84 eV by incorporation of Gr. Furthermore, the photoelectrocatalytic and photocatalytic dye degradation examinations showed a substantial impact of Gr on the photocatalytic activity of MFO nanoparticles: a 28-fold increase in the photocurrent and an 8-fold increase in the dye-degradation rate. The density functional theory (DFT) studies on MFO/Gr heterojunction revealed a considerable hybridization between Gr atoms orbitals (2p orbitals) and MFO atoms orbitals (Mg 3 s and Fe 3d orbitals) in the conduction band, which facilitate the transfer of photo-excited electrons from MFO to Gr. Also, the charge density difference at the MFO/Gr interface led to a polarized field at the interface, which is desirable for hindering photogenerated electron-hole recombination in the MFO/Gr nanocomposite. Along with the experimental results, the DFT results also revealed that the MFO/Gr nano-heterostructure is an excellent candidate for photocatalytic applications such as water splitting using sunlight to produce green hydrogen fuel.

Lattice defects and surface adsorption properties of gold-bearing chalcopyrite: A theoretical study based on DFT

Chalcopyrite (CuFeS2), as one of the carrier minerals of gold, undergoes significant alterations in lattice and surface properties upon doping with gold impurities. These changes markedly influence its separation and purification techniques, especially flotation. Using Density Functional Theory (DFT) based on first-principles, we analyze the influence of gold impurities on the lattice defects and surface properties of chalcopyrite. We developed an adsorption model using prop-2-yn-1-yl diethylcarbamodithioate (PDEC), a sulfur ester collector with an ethynyl group, on gold-infused chalcopyrite to elucidate the adsorption mechanism. Our findings indicate that the Au atom primarily occupies interstitial sites within the chalcopyrite lattice, resulting in an expanded lattice structure. Despite the doping, the lattice remains a p-type semiconductor with increased conductivity, facilitated by Au 6 s orbitals contributing to impurity levels within the conduction band from 2 to 4 eV. Additionally, there is a marked rise in spin-up electrons, with Integrated |Spin Density| results showing greater electron localization in Cu15Fe16S32Au and Cu16Fe16S32Au compared to ideal chalcopyrite crystal (Cu16Fe16S32). The Au atom exhibits maximum stability when adsorbed onto the S-Fe bonds on chalcopyrite surfaces, primarily forming covalent bonds through electron acceptance from Fe 3d orbitals. The presence of gold impurities decreases the collector's adsorption energy on the chalcopyrite (112) surface. However, PDEC exhibits enhanced adsorption performance relative to Al-DECDT and Z-200, primarily due to the chelation between thiocarbonyl and ethynyl groups of PDEC and the gold-bearing chalcopyrite (112) surface. Electron donation from Fe 4p orbitals of surface to the S 3 s and 3p orbitals of collector forms a sigma bond, while the ethynyl group undergoes hybridization with the Au 5d orbitals from −5 to −2.5 eV, fostering stable electron transfer.

P–d Orbitals Coupling Heterosites of Ni2P/NiFe‐LDH Interface Enable O─H Cleavage for Water Splitting

AbstractElectrocatalytic water splitting for hydrogen production still faces a bottleneck due to sluggish reactive kinetics and high reactive energy barriers. Herein, p–d orbital coupling P–Fe heterosites are constructed at Ni2P–FeNi‐LDH interfaces to enhance the O─H bond cleavage of reaction intermediates H2O* and OH* for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. The Ni2P/NiFe‐LDH heterostructure shows superior HER and OER activities for alkaline water splitting with overpotentials of 230 and 270 mV at 100 mA cm−2, respectively, and even exhibits high activity for electrocatalytic alkaline seawater splitting. The interaction of P 2p and Fe 3d orbitals at Ni2P–FeNi‐LDH interfaces upshifts the d‐band center of Fe and downshifts the p‐band center of P. This finding not only facilitates the dissociation of O─H bonds in H2O and promotes the Volmer–Heyrovsky step for HER, but also reduces the energy barrier for the rate‐determining step of OER from OH* to O* transition. This work proposes a new approach to constructing p–d heterosites at heterojunctions to facilitate reactive kinetics and reduce the energy barrier for electrocatalysis.

First-principles study of electronic and magnetic properties of Fe atoms on Cu2N/Cu(100)

Abstract First-principles calculations were conducted to investigate the structural, electronic, and magnetic properties of single Fe atoms and Fe dimers on Cu2N/Cu(100). Upon adsorption of an Fe atom onto Cu2N/Cu(100), robust Fe–N bonds form, resulting in the incorporation of both single Fe atoms and Fe dimers within the surface Cu2N layer. The partial occupancy of Fe-3d orbitals lead to large spin moments on the Fe atoms. Interestingly, both single Fe atoms and Fe dimers exhibit in-plane magnetic anisotropy, with the magnetic anisotropy energy (MAE) of an Fe dimer exceeding twice that of a single Fe atom. This magnetic anisotropy can be attributed to the predominant contribution of the component along the x direction of the spin–orbital coupling Hamiltonian. Additionally, the formation of Fe–Cu dimers may further boost the magnetic anisotropy, as the energy levels of the Fe-3d orbitals are remarkably influenced by the presence of Cu atoms. Our study manifests the significance of uncovering the origin of magnetic anisotropy in engineering the magnetic properties of magnetic nanostructures.

Research on the electronic properties of TiC/γ-Fe and TiB2/γ-Fe interfaces based on first-principles calculations

Addressing the unclear understanding of the bonding mechanisms at the TiC/γ-Fe and TiB2/γ-Fe interfaces, the atomic structure, adhesive work, and electronic properties of the TiC (111)/Fe (111) and TiB2 (001)/Fe (111) interfaces were investigated using first-principles calculations. The results reveal that the C-terminated surface of TiC (111) and the B-terminated surface of TiB2 (001) exhibit high surface activity, facilitating their binding with the Fe (111) surface. The adhesive energy at the TiC (111)/Fe (111) interface is 13.04 J/m2, with a wetting angle of 41.32°, while at the TiB2 (001)/Fe (111) interface, the adhesive energy and wetting angle are 6.08 J/m2 and 74.69°, respectively. TiC demonstrates better wettability and stronger binding strength with γ-Fe surface. At the interface, the C-p orbitals and B-p orbitals hybridize with Fe-d orbitals to form bonds. The population of Fe-C bonds and Fe-B bonds is 0.46 and 0.02, respectively, indicating that Fe-C bonds exhibit covalent characteristics, while Fe-B bonds display ionic characteristics, with Fe-C bonds being stronger than Fe-B bonds. Statistical analysis of charge distribution and charge difference reveals electron accumulation near C and B atoms at the interface. Moreover, the electron transfer at the TiC (111)/Fe (111) interface is significantly greater than that at the TiB2 (001)/Fe (111) interface, which is the fundamental reason for the higher binding strength at the TiC (111)/Fe (111) interface.

Research on the electronic properties of TiB2/γ-Fe(1 1 1) and TiB2/Ni(1 1 1) interfaces

In order to explore the interfacial bonding mechanisms of TiB2/γ-Fe and TiB2/Ni in the composites, the adhesion work, electronic properties and fracture toughness of the TiB2(001)/ γ-Fe(111) and TiB2(001)/Ni(111) interfaces were investigated using first-principles calculations. The results reveal that the surface energy of the TiB2 surface at the B-terminated is the smallest and the constructed TiB2(001)/ γ-Fe(111) interface has the largest adhesive energy. The electronic structures of the TiB2(001)/γ-Fe(111) and TiB2(001)/Ni(111) interfaces reveal that bonding at the interfaces is provided by the B-2p orbitals with the Fe-3d and Ni-3d orbitals, respectively, and that the formation of Fe-B and Ni-B covalent/ionic bonds is the main source of bonding and interaction. The bonding and strength of Fe-B in the TiB2(001)/γ-Fe(111) interface is stronger than that in the TiB2(001)/Ni(111) interface, which is due to the higher charge density accumulation of Fe atoms at the TiB2(001)/γ-Fe(111) interface. Using Griffith’s theory, the TiB2(001)/γ-Fe(111) interface is inferred to have the strongest fracture toughness. This study suggests that the chemical bonding stronger Fe-B bonds result in a high bond strength and a more stable interfacial structure at the TiB2(001)/ γ-Fe(111) interface, leading to better resistance to cracking in practice.

Optimal Oxophilicity at the Fe-Nx Interface Enhances the Generation of Singlet Oxygen for Efficient Fenton-Like Catalysis.

In the pursuit of efficient singlet oxygen generation in Fenton-like catalysis, the utilization of single-atom catalysts (SACs) emerges as a highly desired strategy. Here, a discovery is reported that the single-atom Fe coordinated with five N-atoms on N-doped porous carbon, denoted as Fe-N5/NC, outperform its counterparts, those coordinated with four (Fe-N4/NC) or six N-atoms (Fe-N6/NC), as well as state-of-the-art SACs comprising other transition metals. Thus, Fe-N5/NC exhibits exceptional efficacy in activating peroxymonosulfate for the degradation of organic pollutants. The coordination number of N-atoms can be readily adjusted by pyrolysis of pre-assembly structures consisting of Fe3+ and various isomers of phenylenediamine. Fe-N5/NC displayed outstanding tolerance to environmental disturbances and minimal iron leaching when incorporated into a membrane reactor. A mechanistic study reveals that the axial ligand N reduces the contribution of Fe-3d orbitals in LUMO and increases the LUMO energy of Fe-N5/NC. This, in turn, reduces the oxophilicity of the Fe center, promoting the reactivity of *OO intermediate-a pivotal step for yielding singlet oxygen and the rate-determining step. These findings unveil the significance of manipulating the oxophilicity of metal atoms in single-atom catalysis and highlight the potential to augment Fenton-like catalysis performance using Fe-SACs.

Mott-Insulator State of FeSe as a Van der Waals 2D Material Is Unveiled.

We undertook a comprehensive investigation of the electronic structure of FeSe, known as a Hund metal, and found that it is not uniquely defined. Through accounting for all two-particle irreducible diagrams constructed from electron Green's function G and screened Coulomb interaction W in a self-consistent manner, a Mott-insulator phase of 2D-FeSe is unveiled. The metal-insulator transition is driven by the strong on-site Coulomb interaction in its paramagnetic phase, accompanied by the weakening of both local and nonlocal screening effects on the Fe-3d orbitals. Our results suggest that Mott physics may play a pivotal role in shaping the electronic, optical, and superconducting properties of monolayer or nanostructured FeSe.

Exciton Dissociation into Charge Carriers in Porphyrinic Metal-Organic Frameworks for Light-Assisted Li-O2 Batteries.

Light-assisted Li-O2 batteries exhibit a high round-trip efficiency attributable to the assistance of light-generated electrons and holes in oxygen reduction and evolution reactions. Nonetheless, the excitonic effect arising from Coulomb interaction between electrons and holes impedes carrier separation, thus hindering efficient utilization of photo-energy. Herein, porphyrinic metal-organic frameworks with (Fe2Ni)O(COO)6 clusters are used as photocathodes to accelerate exciton dissociation into charge carriers for light-assisted Li-O2 batteries. The coupling of Ni 3d and Fe 3d orbitals boosts ligand-to-metal cluster charge transfer, and hence drives exciton dissociation and activates O2 for superoxide (•O2 -) radicals, rather than singlet oxygen (1O2) under photoexcitation. These enable the light-assisted Li-O2 batteries with a low total overvoltage of 0.28V and round-trip efficiency of 92% under light irradiation of 100mW cm-2. This work highlights the excitonic effect in photoelectrochemical processes and provides insights into photocathode design for light-assisted Li-O2 batteries.

Yu–Shiba–Rusinov states induced by single Fe atoms on reconstructed compound superconductor V[formula omitted]Si

Reconstructed surfaces of the A15-compound superconductor V3Si(100) that are possibly induced by the segregation of bulk impurities serve as platforms to study the dependence of Yu–Shiba–Rusinov states induced by a single Fe atom on the adsorption site. Their number, energy and electron–hole asymmetry vary strongly with the atomic environment of the Fe atom. These variations are indicative of different Fe d-orbitals being active in the site-dependent exchange coupling with the substrate Cooper pairs. Spatially resolved spectroscopy gives rise to a short decay length of the Yu–Shiba–Rusinov states and thereby suggests the three-dimensional character of the scattering process underlying the bound states.

A case study on the recovery of unevenly embedded particle size in high-carbon chalcopyrite using an alkyne-based thioester collector: Flotation processing and adsorption mechanism

The difference in chalcopyrite's primary ore-hosting rocks (dolomite and carbonaceous slate) in the Democratic Republic of the Congo results in an extremely uneven grain size distribution. Additionally, the presence of 2.21% organic carbon in the gangue impacts flotation efficiency. To address these challenges, ore properties were analyzed using the Mineral Liberation Analyzer (MLA), X-Ray Diffractometer (XRD), and microscopy. Flotation process was modified to incorporate a "middlings regrinding" processing, utilizing PDEC (an alkyne-based thioester collector, prop-2-yn-1-yl diethylcarbamodithioate) as the collector for experimental studies. Density Functional Theory (DFT) calculations elucidated the interaction mechanism of PDEC on chalcopyrite's surface. The MLA analysis indicates that chalcopyrite is mainly found in medium to fine grains, with the presence of fine-grained copper minerals smaller than 0.04mm accounting for 16.29% of the sample. This implies that these minerals require fine grinding for effective separation. Despite interference from organic carbon, PDEC demonstrates remarkable selectivity and efficiency in chalcopyrite flotation. By employing the "middlings regrinding" flotation method, a concentrate with a Cu content of 26.79% and a recovery of 87.88% was achieved, representing an increase of 0.17% in Cu grade and 4.09% in recovery rate compared to the conventional flotation process. DFT analysis demonstrates that the S 3p orbitals in carbon-sulfur double bond of PDEC and the C 2p orbitals in its acetylene group significantly affect its collection efficiency, engaging in hybridization with the Fe 3d orbitals on the surface of chalcopyrite, thereby facilitating a robust bonding interaction.

Effect of Y element on atomic structure, glass forming ability, and magnetic properties of FeBC alloy

Abstract The atomic structure of amorphous alloys plays a crucial role in determining both their glass-forming ability and magnetic properties. In this study, we investigate the influence of adding the Y element on the glass-forming ability and magnetic properties of Fe86−x Y x B7C7 (x = 0, 5, 10 at.%) amorphous alloys via both experiments and ab initio molecular dynamics simulations. Furthermore, we explore the correlation between local atomic structures and properties. Our results demonstrate that an increased Y content in the alloys leads to a higher proportion of icosahedral clusters, which can potentially enhance both glass-forming ability and thermal stability. These findings have been experimentally validated. The analysis of the electron energy density and magnetic moment of the alloy reveals that the addition of Y leads to hybridization between Y-4d and Fe-3d orbitals, resulting in a reduction in ferromagnetic coupling between Fe atoms. This subsequently reduces the magnetic moment of Fe atoms as well as the total magnetic moment of the system, which is consistent with experimental results. The results could help understand the relationship between atomic structure and magnetic property, and providing valuable insights for enhancing the performance of metallic glasses in industrial applications.

DFT and Monte Carlo investigations of electronic structure, magnetic, magnetocaloric, and thermoelectric properties of the perovskite SrXO3 (X = Mn and Fe) compound

The structural, electronic, magnetic, magnetocaloric, and thermoelectric properties of the SrXO3 (X = Mn and Fe) perovskite compounds were investigated using first-principles calculations. It was observed that the SrXO3 compounds are G-anti-ferromagnetic perovskites with partial magnetic moment with a value of 2.7 [Formula: see text] and 2.4 [Formula: see text] for Mn-3d and Fe-3d orbitals for SrMnO3 and SrFeO3, respectively. Moreover, by using Monte Carlo simulation (MCs) combined with the Metropolis algorithm, the calculated coupling interactions between the magnetic atoms Mn–Mn and Fe–Fe are [Formula: see text][Formula: see text]meV and [Formula: see text][Formula: see text]meV for SrMnO3, [Formula: see text][Formula: see text]meV and [Formula: see text][Formula: see text]meV for SrFeO3, respectively. Furthermore, a significant magnetocaloric effect (MCE) was observed around the Néel temperature of [Formula: see text][Formula: see text]K (for SrMnO3) and [Formula: see text][Formula: see text]K (for SrFeO3), and the maximal simulated magnetic entropy and relative cooling power values of all the studied compounds are found to be 100[Formula: see text]J/kg (for SrMnO3) and 110[Formula: see text]J/kg (for SrFeO3), respectively, with an applied magnetic field of [Formula: see text] T. These results are in complete agreement with the experimental results and more specifics than other theoretical calculations. Hence, SrXO3 compounds are considered promising candidates for magnetic refrigeration at low temperature.