Electron Energy Research Articles

Synchrotron self-Compton in a radiative-adiabatic fireball scenario: Modelling the multiwavelength observations in some Fermi/LAT bursts

Abstract Energetic GeV photons expected from the closest and the most energetic Gamma-ray bursts (GRBs) provide an unique opportunity to study the very-high-energy emission as well as the possible correlations with lower energy bands in realistic GRB afterglow models. In the standard GRB afterglow model, the relativistic homogeneous shock is usually considered to be fully adiabatic, however, it could be partially radiative. Based on the external forward-shock scenario in both stellar wind and constant-density medium. We present a radiative-adiabatic analytical model of the synchrotron self-Compton (SSC) and synchrotron processes considering an electron energy distribution with a power-law index of 1 < p < 2 and 2 ≤ p. We show that the SSC scenario plays a relevant role in the radiative parameter ε, leading to a prolonged evolution during the slow cooling regime. In a particular case, we derive the Fermi/LAT light curves together with the photons with energies ≥100 MeV in a sample of nine bursts from the second Fermi/LAT GRB catalog that exhibited temporal and spectral indices with ≳ 1.5 and ≈2, respectively. These events can hardly be described with closure relations of the standard synchrotron afterglow model, and also exhibit energetic photons above the synchrotron limit. We have modeled the multi-wavelength observations of our sample to constrain the microphysical parameters, the circumburst density, the bulk Lorentz factor and the mechanism responsible for explaining the energetic GeV photons.

On-demand performance optimization of AlGaN/GaN high electron mobility transistors using stoichiometric variation of dielectric alloy AlxTayO

The current research investigates the potential advantages of optimally combining wide bandgap Al2O3 with high dielectric constant (high-κ) Ta2O5 for gate dielectric applications. Various compositions of 10 nm AlxTayO oxide films are grown on the Al0.3Ga0.7N/GaN heterostructure by co-sputtering Al and Ta metals, followed by thermal oxidation at 500 °C. The average root-mean-square roughness of the grown oxide films is ∼1.2–1.4 nm compared to 0.4 nm for as-deposited metal. X-ray photoelectron spectroscopy and transmission electron microscopyconfirm the formation and thickness of the grown oxide films. The bandgap (Eg) of the oxide films calculated from O1s electron energy loss spectra show a linear increase from 4.85 eV for pure Ta2O5 to 6.4 eV for pure Al2O3. The dielectric constant (εox) calculated from capacitance–voltage (CG−VG) measurements decreases linearly from 25.7 for Ta2O5 to 7.9 for Al2O3. The interface trap density (Dit) is estimated from the frequency dispersion of capacitance–voltage (CG−VG) characteristics. The DC and radio frequency (RF) characteristics of AlxTayO/Al0.3Ga0.7N/GaN high electron mobility transistor (HEMT) devices are measured and compared with the Schottky HEMT devices (without any gate oxide). Compared to Schottky HEMT devices, AlxTayO/Al0.3Ga0.7N/GaN HEMT devices show superior DC characteristics, which helps us achieve maximum RF output power. Furthermore, the OFF-state measurements show that the AlxTayO/Al0.3Ga0.7N/GaN HEMT devices can sustain higher source-to-drain voltages, from a minimum of 88 V on pure Ta2O5 metal-oxide-semiconductor (MOS)-HEMTs to a maximum of 138 V on pure Al2O3 MOS-HEMTs before the dielectric breakdown happens, compared to a 57 V breakdown voltage on Schottky HEMT devices. An oxide variation of AlxTayO, with Al composition ratio of 0.34, shows an exceptional ION/IOFF ratio of 4 × 1011, a gate leakage current of 8 × 10−12 A/mm, a near-ideal subthreshold slope of 63.8 mV/dec, and the unity current gain frequency (fT) of 25.6 GHz.

Ag modified ZnO nanoflower gas sensitive sensor for selective detection of n-butanol

Ag modified ZnO nanoflowers were successfully prepared by sunlight induced solvent reduction method. The samples were characterized by x-ray diffractometer, field emission scanning electron microscope, transmission electron microscope and energy dispersive x-ray spectrum, and the results confirmed the presence of Ag nanoparticles on the ZnO nanoflower. The gas sensing performance of the materials was studied at different operating temperatures and different n-butanol concentrations. The results showed that the Ag modified ZnO nanoflower sensor responded to 50 ppm n-butanol up to 147.17 at 280 °C, and the Ag modified ZnO nanoflower sensor exhibited excellent repeatability, stability and response recovery time. In addition, different target gases were employed for the selectivity study of the Ag modified ZnO nanoflower. It can be found that the Ag modified ZnO nanoflower had good selectivity for n-butanol. The improved response of the Ag modified ZnO nanoflower sensor was attributed to the catalytic effect of Ag nanoparticles. The results indicate that the Ag modified ZnO nanoflower will become a very promising sensing material for n-butanol gas detection.

Transformation Dynamics of Nanosized Bi Films into Semiconductor Films of Bismuth Oxide in the Cold Plasma Device

This work proposes an original method that reveals the transformation dynamics of nanosized Bi films into semiconductor films of bismuth oxide (Bi2O3) and the factors affecting the low‐energy cold plasma on the electro‐optical properties of Bi2O3. In the plasma microreactor with a photosensitive GaAs:Cr electrode, the transformed Bi films 400–1100 nm thick are analyzed by X‐ray diffraction to determine the crystal structure of Bi2O3 and by an electron probe microanalyzer to explore the evolution of the composition. The morphological properties of the Bi films exposed to electron–ion flow are examined by processing the scanning electron microscope images. It is found that as a result of the combined effect of photoactive illumination, charged particles, and active plasma components: 1) an absorption spectrum of a new substance is formed in the range λ = 330–1100 nm; 2) the optical width of the bandgap of the resulting substance is Eg ≈ 3 eV, which satisfactorily coincides with the width of the bandgap of Bi2O3; and 3) to overcome the potential barrier and formation of semiconducting Bi2O3 film energy is required, which is provided by the combined kinetic energy of electrons and negatively charged oxygen ions bombarding on the Bi film.

Epitaxial growth and band offsets of β -(ScxGa1− x)2O3 thin films grown on (100) β -Ga2O3 substrate

β-(ScxGa1−x)2O3 (x = 0–0.36) thin films were epitaxially grown on (100) β-Ga2O3 substrates by oxygen-radical-assisted pulsed-laser deposition. β-(ScxGa1−x)2O3 epilayers were coherently strained up to x = 0.30, although the presence of a structural disorder was implied when x > 0.2. The bandgap energies measured by reflection electron energy loss spectroscopy increased from 4.56 to 5.25 eV with increasing Sc content. In β-(ScxGa1−x)2O3 epilayers, a slightly negative bandgap bowing behavior with a bowing parameter of −0.4 eV was observed, resulting in a larger bandgap increase than in β-(AlxGa1−x)2O3 epilayers with identical x. X-ray photoemission spectroscopy measurement revealed that the valence-band and conduction-band offsets of β-(Sc0.17Ga0.83)2O3 epilayer with respect to β-Ga2O3 were 0.0 and 0.3 eV, respectively.

Energy band management of corn-like ZnO/Ag2S heterojunctions for efficient light harvesting and enhanced photocatalysis.

Corn-like ZnO/Ag2S heterojunctions are designed and prepared by the solvothermal method and the subsequent covering process. They construct a type II core-shell heterojunction structure. This structure adjusts the relative positions of electron energy levels and generates a strong and broad absorption band, while emitting weak visible light. It also facilitates the transfer of photoexcited carriers through the interface and the confinement of the same by the different components of the nanostructure. Separation of electrons and holes makes them possible to drift to the surface of ZnO and Ag2S and to participate in the redox reactions. In addition, the presence of many defects produces many active sites on the surface of the lattice. So, the ZnO/Ag2S heterojunctions exhibit excellent photocatalytic properties in the first and second cycles of the photocatalytic process. It degrades 97.7% Rhodamine B only in 18min. This study plays a significant role in promoting visible light catalysis, the efficiency of wastewater treatment technology, and the water environment on the earth.

Electron Irradiation on Metal Oxide Silicon Field Effect Transistors in Space Applications

The space environment is hostile to most semiconductor electronic devices and components used for space applications. The radiation generally encountered in space are α, β, γ, x-ray, energetic electrons, protons, neutrons and ions of various kinds. Especially the Van Allen Belts consist of high energy electrons which are in continuous motion. Satellites systems operating in Low Earth Orbits (LEO) are prone to get exposed to high energy electrons. This paper describes the effect of electron beam irradiation on MOSFETs planned for space applications. The devices selected for the study are 2N6768 n- channel MOSFETs (JANTXV) procured from ISAC, Bangalore. The decapped MOSFETS are exposed to a beam of electrons for various doses ranging from 50 Gy to 10 KGy in the electron energy range 7 – 10 MeV using the electron accelerator facility at RRCAT, Indore. Pre and post- irradiation measurements of the electrical characteristics are undertaken to investigate the electron induced device degradation and damage. The dominant mechanism of the interaction of the electrons with semiconductors is to produce atomic displacement which can have serious impact on electrical characteristics. MOS (Metal oxide semiconductor) devices are the most sensitive of all semiconductor devices to radiation showing considerable degradation even for a relatively low dose of exposure to high energy electrons. The energy dissipated by electrons in semiconductors is sufficient to displace silicon atoms and causes a shift in the threshold voltage and leakage current. The study indicates that the gate threshold voltage substantially decreases with the increase in electron dose. The leakage current increases with dose which could have an impact on the performance of the device. The transconductance of the MOS transistor is found to decrease with increase in electron dose. The observed changes in the electrical characteristics upon electron irradiation are analysed and interpreted as due to trapped charges in the SiO2 layer and at the interface. The present investigation reveals that there is a remarkable degradation in threshold voltage and the leakage current displays substantial increase when the devices are exposed to electrons. This increase in leakage current can have significant impact on device performance in a radiation environment.

Synergistic inhibition effect of diolefinic dye and silver nanoparticles for carbon steel corrosion in hydrochloric acid solution

The current work looks at the inhibitory effects of a diolefinic dye, namely 1,4-bis((E)-2-(3-methyl-2,3-dihydrobenzo[d]thiazol-2-yl) vinyl) benzene iodide salt, in relation to CS corrosion mitigation in hydrochloric acid (HCl) environment. This study uses a variety of experimental methodologies, including weight loss (WL) analysis, electrochemical tests, and theoretical considerations. The synergistic effect of diolefinic dye and AgNPs on the corrosion inhibition of CS in 1 M HCl was investigated. The inhibition efficiency (IE) displays a notable enhancement as the concentration of the dye is elevated and as the temperature raises the IE increases. The diolefinic dye exhibited % IE of 83% even at low concentration (1 × 10–4 M) whereas 90% in the presence of (2.26 × 10–10) AgNPs. Tafel graphs demonstrate that the dye follows a mixed type inhibitor. The adsorption of the dye on CS surface follows Langmuir model. Moreover, the influence of temperature and the activation parameters disclose that diolefinic dye is chemisorbed on the CS surface. The synergistic coefficient of the diolefinic dye and AgNPs under various concentration conditions was greater than unity. The surface morphology of CS sheets was confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). Density Functional Theory (DFT) calculations provide theoretical support for the inhibitory effects of the examined dye. Notably, there is a high agreement between the findings of practical studies and theoretical expectations.

Cu-Atom Locations in Rocksalt SnTe Thermoelectric Alloy.

The development of functional thermoelectric materials requires direct evidence of dopants' locations to rationally design the electronic and phononic structure of the host matrix. In this study, Cs-corrected scanning transmission electron microscopy and energy dispersive X-ray spectroscopy is employed at the atomic scale to identify Cu atoms' locations in a Cu-doped SnTe thermoelectric alloy. It is revealed that Cu atoms in the rocksalt SnTe form solid solutions at both Sn and Te sites, contrary to their electronegativity order and the intentional Cu doping at Sn sites. Cu atoms are also located at the tetrahedral and crowdion sites of the face-centred cubic structure, with varying degrees of correlations. Such high flexibility of Cu atoms in the rocksalt SnTe offers diverse phonon-scattering mechanisms conducive to the ultra-low lattice thermal conductivity of singly Cu-doped SnTe. This study offers atomic-scale insights for achieving more precise dopant engineering, leading to the accelerated development of functional thermoelectric materials.

Mathematical model of thermocurrents based on calculation of electrical resistance and thermopower as an integral over electron energy

Mathematical model of thermocurrents based on calculation of electrical resistance and thermopower as an integral over electron energy

Apparent effective ionization coefficient in N2 and O2 gas mixtures determined with two separate methods

N2:O2 gas mixtures are important for applications of atmospheric pressure plasmas such as ozone production, air purification from VOCs and NOx and surface treatments. Fundamental parameters such as the effective ionization coefficient are inputs for theoretical plasma models for applications and must thus be accurately known. This work determined the apparent effective ionization coefficient in N2:O2 mixtures in a broad reduced electric field strength E/N range of 150–1200 Td with two separate methods and compared with BOLSIG+ calculations of reduced effective ionization coefficient. Additionally, the equilibrium distance required to establish a steady-state electron energy distribution was estimated from spatial profiles of optical emission.

Effect of BaSO4 on Phase Transformation and Microstructure of CaOFe2O3TiO2 System During Sintering

The Fe2O3CaOTiO2BaSO4 system is established through miniature sintering experiments to reveal the mechanism of BaSO4 and vanadium‐titanium magnetite (VTM) with the help of X‐ray diffraction, scanning electron microscope and energy dispersive spectroscopy, and thermogravimetry. The results show that in the absence of BaSO4, the phase of the sinter consists of CaFe2O4, TiO2, Fe2O3, CaTiO3, and CaFe2O5. When the content of BaSO4 is 1% and 2%, CaTiO3 decreases and the number of needle‐like CF increases. Some Ba2+ solidly dissolve into CF and CaTiO3 to form trace BaFe12O19 and BaTi2O5. When the content of BaSO4 increases to 4%, the CaSO4 phase appears, the formation of C2F is accelerated, and the content of CF and CaTiO3 continues to decline. The needle‐like calcium ferrate gradually transforms into columnar and lamellar. As the BaSO4 content continues to increase to 6% and 8%, although the trend of each phase is similar to that at 4%, it is almost entirely composed of columnar calcium ferrite, barium ferrite, and incomplete tetragonal and rhombic Fe2O3. The results of the study provide a theoretical basis for the utilization of VTM and barium‐containing iron ores in practical production.

Mechanical property and microstructure of fly ash-based geopolymer by calcium activators

Geopolymer is a green and environmentally friendly new type of gel material generated from the reaction of activators with silica-alumina raw materials, possessing extensive research and application value. Fly ash can be used as reaction material, enabling the industrial solid waste to be recycled and reused. In this paper, unconfined compressive strength test, X-ray diffraction analysis, Fourier transform infrared light, 29Si nuclear magnetic resonance, scanning electron microscope and energy disperse spectroscopy, and physisorption experiment were carried out to study the effects of the type and dosage on the mechanical property and microstructure of fly ash-based geopolymer activated by calcium hydroxide, calcium sulfate and their compound. The results indicated that calcium hydroxide and calcium sulfate can promote the dissolution of fly ash crystals, providing adequate Ca2+ for the formation of gel products. The products of calcium hydroxide and calcium sulfate activation are hydrated calcium aluminate, hydrated calcium sulfate, and ettringite, respectively. The effect of the compound activator is superior to that of single activators. With the increase of the proportion of calcium hydroxide, the reorganization and polymerization of gel products were accelerated so that the integrity and continuity of the microstructure of geopolymer were improved, and then the strength increased. When the ratio of calcium hydroxide to calcium sulfate was 3:1 and the total dosage was 20 %, the unconfined compressive strength reached the maximum value. According to this study, it was investigated that type and dosage of calcium activators had evident influence on the geopolymerization of fly ash. And the reutilization and resource utilization of fly ash waste can be achieved, which can provide an engineering theoretical basis for using fly ash-based geopolymer to alter the physical and chemical properties of special soils and achieve solidification effect.

TEM-EELS analysis reveals the W-atom mediated radiation-induced amorphization in M23C6

To gain a mechanistic understanding of the phase stability of M23C6 upon irradiation, the bulk W-doped M23C6 (Cr-W-C system) in the range of 0–12 at.% W concentration was prepared and subjected to helium beam irradiation, following with a thorough electron energy loss spectroscopy (EELS) analysis. Radiation-induced amorphization (RIA) was observed only at the 4 W sample with a W concentration of ∼12 at.%. Analysis of the low-loss spectrum showed that the inelastic mean free path (λ) could be applied an effective indicator of the presence of an amorphous phase. The white line ratio of the carbon K-edge spectrum showed that the chemical bonding state in the crystalline state is mainly 2p3/2 bonding, and it changes to dominantly 2p1/2 bonding accompanying with the crystal-to-amorphous (c-a) transition. Discussion on the relationship between the change in λ (Δλ) and the lattice parameter (Δa) due to irradiation reveals that Δa is not dependent on Δλ, indicating that Δλ is mainly caused by the volume expansion due to the c-a transition. In addition, a crystalline state is remained even after a lattice parameter change of ∼1.5 % in 0 W and 1W-samples, whereas, a lattice expansion of ∼0.2 % would trigger the occurrence of crystal-to-amorphous transition in the 4W-sample. The detailed EELS analysis demonstrated that the constitutional W atoms play an important role in facilitating the occurrence of RIA in M23C6, that is, the phase instability accompanying the lattice expansion due to irradiation was emphasized by the addition of W in M23C6. The insights obtained here suggest that a higher W concentration in M23C6 is more susceptible to RIA, and therefore the resistance to amorphization is achievable by decreasing the W concentration in the steels.

A model for fast electron-driven high-density plasma in the double-cone ignition scheme

Abstract A model for fast electron-driven high-density plasma is proposed to describe the effect of injected fast electrons on the temperature and inner pressure of the plasma in the fast heating process of the double-cone ignition (DCI) scheme. Due to the collision of the two low-density plasmas, the density and volume of the high-density plasma vary. Therefore, the ignition temperature and energy requirement of the high-density plasma vary at different moments, and the required energy for hot electrons to heat the plasma also changes. In practical experiments, the energy input of hot electrons needs to be considered. To reduce the energy input of hot electrons, the optimal moment and the shortest time for injecting hot electrons with minimum energy are analyzed. In this paper, it is proposed to inject hot electrons for a short time to heat the high-density plasma to a relatively high temperature. Then, the alpha particles with the high heating rate and PdV work heat the plasma to the ignition temperature, further reducing the energy required to inject hot electrons. The study of the injection time of fast electrons can reduce the energy requirement of fast electrons for the high-density plasma and increase the probability of successful ignition of the high-density plasma.

Approach to Design Sustainable Alkali-Activated Slag Recycled Aggregate Concrete: Mechanical and Microstructural Characterization

There is a steep increase in demand for concrete as the need for infrastructure is increasing with a rapid increase in urbanization. Consequently, there has been a surging demand for cement across the globe. By using alkaline concrete activated with ground granulated blast furnace slag (GGBS), cement usage can be eliminated in concrete, which addresses the issue of CO2 emissions concerned with the cement manufacturing process and promotes the use of industrial by-products as sustainable building materials. The current study focuses on proposing a methodology to design sustainable GGBS-based alkali-activated concrete incorporated with 100% coarse recycled coarse aggregates (RCA) recovered from construction and demolition (C&D), for various strengths by optimizing the mix proportions and verifying the same through experiments. From the current study, it is evident that this mix design procedure can be adopted to design alkali-activated slag recycled aggregate concrete (AASRAC) mixes for strengths ranging from 44MPa to 85MPa. The optimum values of alkalinity factor (λ) and NaOH concentration (M) i.e., 1.5 and 12, have a significant role in the development of high strengths which is attributed to the formation of hydrotalcite. Micrographs captured using scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) studies reveal that the alkaline binders promote the development of a denser and stronger interfacial transition zone (ITZ) that enhances the strength of lower AA/B concretes at the microstructural level as Ca/Si ratio is higher for lower AA/B concretes. Global warming potential (GWP) analysis reveals that the alkali-activated concretes have significantly lower GWP compared to conventional OPC-based concrete by approximately 2.5 times. The mix-design chart proposed in this study may pave the way to designing structural grade AASRAC with enhanced performance for the desired strength, which may find its application in fast-track construction and manufacturing of prefabricated elements.

Preparation, characterization, and catalytic performance comparison of Ni/LaBO3 and Ru‐Ni/LaBO3 (B = Al, Fe) for methane steam reforming to hydrogen production

AbstractThe methane steam reforming (MSR) reaction is a significant process for hydrogen production, and developing catalysts with high activity and stability is crucial. In this work, the supported perovskite catalysts of Ni/LaBO3 and Ru‐Ni/LaBO3 (B = Al, Fe) were prepared by the sol–gel method using citric acid as a gelling agent for MSR to hydrogen production. The phase composition, pore structure, and surface morphology of the prepared catalysts were characterized by X‐ray diffractometer, Brunauer–Emett–Teller, scanning electron microscopy and energy dispersive spectroscopy, and X‐ray photoelectron spectroscopy. The reaction activity and stability of the prepared catalysts were tested in the fixed‐bed reactor with the temperature range of 500–800°C. The effect of Ru addition on the structure of perovskite and catalytic performance of MSR is explored. The results showed that 1wt%Ru–15wt%Ni/LaAlO3 catalyst exhibited the most excellent activity and stability during the reaction compared with the other three catalysts. The CH4 conversion, H2 selectivity, and H2 yield of the 1wt%Ru–15wt%Ni/LaAlO3 catalyst could reach 94.68%, 79.78%, and 48.65%, respectively, under the reaction temperature of 800°C and gas hourly space velocity of 36 000 mL/(gh), which were higher than those of a commercial catalyst. It was because that the relatively large surface area of perovskite support provides more active site and the addition of Ru enable Ni to have a smaller size and more dispersion. This study could provide a reference of perovskite catalysts for hydrogen production by MSR.

Characterization of Nickel Cladding on Type 316H Stainless Steel for Enhanced Corrosion Resistance in Molten Chloride Salts

This study explores the corrosion protection characteristics of nickel (Ni) cladding on Type 316H stainless steel in molten chloride salt environments, relevant to molten salt reactors (MSRs) which are gaining interest as advanced and sustainable nuclear energy sources. Type 316H stainless steel, while noted for its high-temperature strength and corrosion resistance, faces significant challenges when exposed to corrosive molten salts. To address this, Ni cladding was applied using gas tungsten arc (GTA) welding and directed energy deposition (DED) laser cladding. Characterization of the cladding layers was performed using field-emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS), identifying precipitates such as Ti(C,N) and Cr₂O₃. Mechanical integrity was verified through bending tests in accordance with ASTM E190-21, which revealed no cracks in the cladding layers. Corrosion resistance was assessed through immersion tests in a 57 mol% NaCl - 43 mol% MgCl₂ mixture at 650°C for 502 hours. Results demonstrated superior corrosion resistance of Ni-clad specimens compared to uncoated Type 316H stainless steel and Incoloy 800H, with the Ni cladding exhibiting a weight increase due to Fe deposition from the Fe-base alloys. The study concludes that Ni cladding, irrespective of the application method, enhances the durability and longevity of Type 316H stainless steel in the harsh environments typical of MSRs, suggesting a promising approach to improving the performance of structural materials in these systems.

Tuning the optical and photophysical characteristics of DR1 through mixing with JGB

A dye mixture of Disperse red1 (DR1) and Janus green B (JGB) was prepared with different concentrations of the two dyes. The optical properties were studied for the two dyes and their mixtures in terms of the absorbance spectra. The direct optical energy gap in addition to the refractive index, extinction coefficient, dielectric constant and optical conductivity were estimated to the two dyes and their mixtures. The experimental energy gap was found to be 2.234 and 1.666 eV for DR1 and JGB respectively, while the values of the energy gaps for the mixtures were found to be ranging between these two values. On the other hand, the refractive index was found to be changed in a systematic way by changing the contents of the dye mixture. The same behavior was also observed for the dielectric constant and optical conductivity. The emission of the two dyes and their mixtures was studied in terms of fluorescence spectra using excitation wavelength of 300 nm where a change in the fluorescence intensity was observed by changing the contents of the mixture. Finally, TD-DFT simulations were performed for the two dyes and their mixture to study the electron density, electrostatic potential, energy gap and optical absorption spectrum and found to be compatible with the experimental measurements.

Comparative investigation of composition, microstructure and property influences on electrocatalysis of two representative cathodes: BaCo0.4Fe0.4Zr0.1Y0.1O3-δ versus Ba0.5Sr0.5Co0.8Fe0.2O3-δ

BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) and Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) perovskites are two representative high-performance cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Here, symmetric cell tests demonstrate that polarization resistance values of BCFZY cathode are only 0.21–0.29 times those of BSCF cathode at 740–660 °C, and 0.21–0.26 times those of BSCF cathode at the oxygen partial pressures of 1.00–0.10 atm. Distribution of relaxation times (DRT) is applied to detect individual electrode processes overlapped in impedance spectra, which finds that the dominant processes of oxygen dissociation, subsequent species transfer and reduction on BCFZY cathode are superior to those of BSCF cathode. By temperature-programmed desorption of oxygen (O2-TPD), thermal expansion coefficient (TEC) measurements, scanning electron micrograph (SEM) and energy dispersive spectra measurements, the strong oxygen combination ability with higher activation energy of oxygen desorption (Ed = 84 kJ/mol), peculiar surface state with evident nano-particle structure, more matchable TEC (19.0 × 10-6 K−1) and excellent interfacial connection with the electrolyte are observed on BCFZY cathode to account for its distinctive catalysis, as compared to BSCF cathode (Ed = 68 kJ/mol, TEC = 24.2 × 10-6 K−1).