SrO Phases Research Articles

Investigation of electrochemical and photoluminescence properties of Dy[formula omitted] doped SrO/BaO/Al2O3 nanocomposite for supercapacitor and display applications

The current study investigates the synthesis and characterization of dysprosium-doped strontium barium aluminum nanocomposites (SBAD NCs), aiming to enhance their suitability for display and supercapacitor applications. SBAD NCs are synthesized by Solution combustion synthesis using aloevera extract as a reducing agent. Multi-phase formation of NCs due to SrO, BaO, and γ-Al2O3 phases was confirmed by PXRD analysis, and crystallite size is found to be in the range of 26 nm to 36 nm. SEM analysis confirmed the surface morphology and the elemental composition was affirmed by the EDAX spectrum which confirmed the purity of the synthesis. The blue shift in the UV–visible absorption peak with increasing dopant concentration suggests a rise in the direct energy band gap from 4.07 eV to 4.11 eV. FTIR analysis confirmed functional groups and fingerprint region affirmed the presence of SrO, BaO, and AlO bonds. Photoluminescence analysis performed under excitation wavelength 276 nm revealed a prominent emission peak at 565 nm, and the CIE values fall in the yellow-green region of visible spectra. The CCT value was found to be 4490 K–4542 K which might find an application as a nanophosphor in cool light-emitting diodes. The tailored nanocomposites exhibit exceptional electrochemical performance characterized by superior specific capacitance, and improved charge–discharge kinetics, as evaluated through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The specific capacitance is found to be in the range of 103.26 F/g to 173.24 F/g at a scan rate of 10 mV/s with increasing Dy3+ dopant concentration from 1 mol% to 9 mol% respectively. The dysprosium-doped SBAD NCs emerge as promising candidates for high-performance energy storage systems and vibrant display technologies, offering a synergistic integration of efficient energy storage and vivid display functionalities.

Enhancing LSCF-based air electrode durability: Insights into sulfur poisoning and air purification

The electrochemical performance of perovskite-type air electrodes in solid oxide cells is strongly affected by a trace amount of SO2 as the air impurity. The present work aims to study air purification efficiency in suppressing the degradation rate for the LSCF-GDC air electrode while operating under different SO2 concentrations. For this purpose, the electrochemical performance of symmetrical cells was evaluated using impedance spectra measured over 320 h and compared with intrinsic electrode degradation in synthetic air. Accordingly, the intrinsic degradation rate was measured at 0.05 mΩ cm2 h−1 while exposing the cell to synthetic air containing 10 and 100 ppb SO2, causing a severe increase to 0.17 and 0.30 mΩ cm2 h−1, respectively. Nevertheless, the calculated degradation rate under purified air containing 100 ppb SO2 was similar to the LSCF-GDC intrinsic degradation rate, representing the high practicality of filter material to adsorb SO2 species. Interpreting the impedance spectra using a distribution of relaxation times (DRT) and a complex nonlinear least squares fit (CNLS) revealed that the intrinsic degradation mechanisms were the limitation of dissociative surface adsorption of oxygen and charge transfer to the adsorbed oxygen. At the same time, inhibition of the O2 adsorption caused by the deposition of SrO, SO32−, and SrSO4 phases and increasing surface diffusion resistance for the adsorbed oxygen atoms were the rate-determining steps in SO2-containing synthetic air. Lastly, the effective suppression of degradation rate by gas purification indicates an extensive use of filter material to extend the lifespan of SOCs.

Growth and phase transition of Sr3Zr2O7 single crystals

The melting behavior of Ruddlesden-Popper type hybrid improper ferroelectric Sr3Zr2O7 phase in the ZrO2–SrO pseudo-binary system was investigated, and its single crystals were successfully grown. A series of the slow-cooling floating zone experiments revealed that Sr3Zr2O7 melts incongruently into SrZrO3 phase and a liquid and that the compositional range where Sr3Zr2O7 and a liquid coexist is located around 70 mol% SrO composition. Based on the results, we attempted to grow Sr3Zr2O7 single crystals by the traveling solvent floating zone method using SrO-excess solvent and feed. Consequently, many small single crystals of Sr3Zr2O7 phase with several millimeters in size were discovered in the as-grown boules covered with SrO phase. The phase transition behavior of the grown crystals was investigated by differential thermal analysis with polarizing optical microscopy as well as by optical second harmonic generation measurements. We directly observed a reconstruction of orthorhombic twin domains in Sr3Zr2O7 single crystals accompanied by the first-order ferroelectric transition at about 410 °C.

Study of the Electrical Properties and Electrochemical Sensing Efficiency of Hydrothermally Synthesized Sr Doped Nickel Oxide Nanomaterials

Herein, we present pure nickel oxide nanoparticles (NiO NPs) and Sr doped NiO NPs SrxNi1−xO (x = 0.0, 0.01, 0.02, 0.03, 0.04) which are synthesized via hydrothermal approach. As-synthesized samples are analyzed through structural characterization techniques like x-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The single cubic phase is obtained for NiO NPs and the samples with low Sr dopant contents (1% to 2%); however, samples with high Sr dopant contents (3% to 4%) have a secondary phase (SrO phase). The particle size of Sr doped NiO NPs ranges from 50–100 nm, and the particles lose their uniformity as dopant concentration is increases. Electrical and dielectric characteristics of as-synthesized samples are studied, and the effect of Sr dopant contents is discussed. Electrochemical studies reveal that the selected samples exhibit remarkable catalytic activity toward glucose sensing owing to their specific structural and morphological characteristics.

Structural Dependent Eu3+ Luminescence, Photoelectric and Hysteresis Effects in Porous Strontium Titanate.

Eu3+ doped porous nanostructured SrTiO3 films and powder fabricated by sol-gel route without using any precursor template are characterized by different morphology and phase composition. The films and the power show red and yellow luminescence with the most intensive photoluminescence (PL) bands at 612 nm and 588 nm, respectively. Raman, secondary ion mass spectrometry (SIMS), and X-ray diffraction (XRD) analysis of undoped nanostructured porous SrTiO3 films showed the presence of TiO2, SrO, and SrTiO3 phases and their components. The undoped porous SrTiO3 films are photosensitive and demonstrate resistive switching. The capacitance-voltage hysteresis loops with the width of about 6 V in the frequency range of 2 kHz—2 MHz were observed.

A review on recent progress in rare earth and transition metals activated SrY2O4 phosphors

SrY2O4 belongs to the family of AB2O4 (A = alkaline earth metal, B = rare earth element) type spinel oxides. SrY2O4 is an inter oxide in SrO and Y2O3 pseudo-binary phase diagram. It has attracted immense interest as a promising host lattice owing to its thermal and chemical stability. The luminescent characteristics of SrY2O4 phosphors make them promising candidates for field emission displays. In the present review article, recent progress in the synthesis and luminescent properties of bare and doped SrY2O4 phosphors are reviewed. In the first part, different synthesis routes and their resultant outcomes are discussed. Then, the downconversion and upconversion luminescent characteristics of undoped and doped SrY2O4 phosphors are reviewed. The effect of site occupancy, morphology, reaction conditions, different excitation wavelengths, dopant concentrations, and energy transfer mechanisms are explained in detail. In the end, challenges and future scope in luminescence and synthesis of SrY2O4 are proposed. This review article gives a complete summary for the drawbacks and current challenging issues of SrY2O4 phosphors, which can give potential sprout for future work.

Efficient water splitting through solid oxide electrolysis cells with a new hydrogen electrode derived from A-site cation-deficient La0.4Sr0.55Co0.2Fe0.6Nb0.2O3-δ perovskite

Steam splitting using solid oxide electrolysis cells (SOECs) is highly attractive for mass production of high-purity hydrogen, while its economic competitiveness strongly relies on the availability of low-cost, active and stable hydrogen electrodes. Here, we report an A-site cation-deficient La0.4Sr0.55Co0.2Fe0.6Nb0.2O3-δ (LSCFN55) perovskite is such a hydrogen electrode for SOEC, exhibiting a high electrolysis current density of 0.956 A/cm2 with an applied voltage of 1.3 V at 850 °C and good stability in a high humidity and hydrogen partial pressure environment. The introduction of A-site cation deficiency into the perovskite oxide lattice of LSCFN55 promotes the exsolution of partial cobalt and iron from the oxide bulk with the formation of Co2Fe alloy nanoparticles that decorate the surface of perovskite main phase, simultaneously SrO is segregated to form nanocomposites with the alloy. The outstanding electro-catalytic activity of alloy nanoparticles, the favorable water adsorption capability of SrO, the high oxygen-ion conductivity of the perovskite main phase, and the improved electronic conductivity of the material, cooperatively contribute to the superior performance of the electrode. The strong interaction between the alloy nanoparticles and the perovskite substrate effectively suppresses the sintering of the nanoparticles while the SrO phase protects the alloy nanoparticles from oxidation, both then contribute to the high operating stability of the electrode.

Controlled Synthesis of Nanocrystalline Nb:SrTiO3 Electron Transport Layers for Robust Interfaces and Stable High Photovoltaic Energy Conversion Efficiency in Perovskite Halide Solar Cells

Perovskite halides are of great attraction as efficient light absorption materials for solid-state solar cells, but the stability and photovoltaic energy conversion efficiency of perovskite solar cells (PSCs) are still limited by the interface structures and defects between their light-absorbing perovskite halides and electron transport layers (ETLs). Here, we report the ultraviolet (UV) light-induced degradation mechanism at the interfaces between perovskite halide and conventional TiO2 ETL materials and provide a solution to overcome this drawback. UV-induced degradation is shown to be attributed to the formation of oxygen vacancies formed at the perovskite halide–ETL interface under UV light illumination, where the oxygen atoms released at the interface accelerate the decomposition of perovskite halide by inducing chemical reactions. Meanwhile, nanocrystalline SrTiO3 (STO) ETLs are revealed to be tunable in enabling high performance in PSCs under UV light illumination. Indeed, tuning the electronic structure of STO ETLs by Nb doping, in combination with the controllable removal of SrO phases segregated on the Nb-doped STO ETL surfaces, is exhibited to enable robust interface stability and stable high photovoltaic energy conversion efficiency for PSCs. Furthermore, we demonstrate that STO-based PSCs have no hysteresis due to low defect concentrations at the perovskite halide–STO ETL interfaces.

Synthesis and Stability of SrxNiyOz Chromium Getter for Solid Oxide Fuel Cells

Stability of SrO-NiO solid solution synthesized from low cost alkaline earth and transition metal nitrate salts is studied for application as a gaseous chromium getter in solid oxide fuel cells (SOFC). Phase identification and its evolution has been examined using high temperature in-situ X-ray diffraction (HT-XRD) whereas thermal stability and morphology of compounds have been studied using XRD in combination with scanning electron microscopy (SEM). Synthesized SrxNiyOz powder remains stable up to 900°C in air, whereas exposure above 950°C leads to its dissociation into separate SrO and NiO phases. Presence of SrO in powder reacts with H2O and CO2, present in atmospheric air, resulting into pulverization due to volume change and the formation of hydroxides and carbonates. Thermogravimetric analysis (TGA) of the pulverized powders show approximately 20% weight loss due to the evaporation of hydroxyl and carbonate groups. Chemical stability of SrxNiyOz is considered essential in order to prevent pulverization and flaking of the getter coating applied over ceramic honeycomb or foam substrates. Chromium getter is considered a cost effective and reliable means to mitigate cathode poisoning in high temperature electrochemical systems such as solid oxide fuel cells, solid oxide electrolysis cell (SOEC) and oxygen transport membranes (OTM).

Chemical and Structural Stability of SrxNiyOz Chromium Getter for Application in SOFC Systems

Non-noble, non-strategic and cost effective SrxNiyOz based chromium getter is being developed for capturing gas phase chromium species in SOFC power generation systems. In this study, we report the chemical and structural stability of the SrxNiyOz powder under synthesis and operational conditions. Phase stability of SrxNiyOz in the temperature range of 850 °C to 1000 °C has been analyzed by high temperature in-situ X-ray diffraction (XRD) technique and SEM-EDS is used to study the surface morphology. XRD results indicate that the synthesized SrxNiyOz remains stable at 850 °C and 900 °C sintering temperature with no/negligible phase separation into SrO and NiO compounds, whereas exposure to temperatures 950 °C and 1000 °C lead to the dissociation of parent phase into the formation of SrO and NiO phases. Further, it was observed that the powder samples sintered at 950 °C and 1000 °C show volume expansion and pulverization when exposed to the humid air atmosphere for 24 h post sintering at 950 °C and 1000 °C. Samples sintered at 850 °C and 900 °C maintain structural stability and shape.

Bipolar resistive switching and substrate effect in GdK2Nb5O15 epitaxial thin films with tetragonal tungsten bronze type structure

Ferroelectric compound GdK2Nb5O15 with tetragonal tungsten bronze type structure thin films were grown by pulsed laser deposition on (001)SrRuO3/SrTiO3 and (001)SrRuO3/LSCO/MgO substrates respectively, in the same experimental conditions. Structural properties were investigated using X-ray diffraction in different modes. θ–2θ diffraction shows a single crystalline SRO and GKN phases, with c-axis perpendicular to the substrate. Phi-scans show for both SRO and GKN an epitaxial cube-on-cube growth. Reciprocal space mapping (RSM) was performed on GKN to determine the in-plane lattice parameters, and showed that GKN grown on MgO is more constrained comparing to STO. Room temperature electrical properties were investigated using platinum (Pt) top electrodes. Results show that GKN thin films deposited on MgO and STO substrates are resistively switchable. It was found that the nature of the substrate affects strongly the resistance ratio: GKN on SRO/LSCO/MgO showed a large hysteresis comparing to GKN on SRO/STO. Resistance switching in GKN is attributed to the oxygen vacancies migration which can be controlled by the substrate or the frequency sweep.

Effect of temperature on the chromium deposition and poisoning of La0.6Sr0.4Co0.2Fe0.8O3-δ cathodes of solid oxide fuel cells

In this study, the effect of the temperature on the surface segregation and Cr deposition on La0.6Sr0.4Co0.2Fe0.8O3-ä (LSCF) cathodes is investigated using confocal laser Raman spectroscopy and electrical conductivity relaxation (ECR) method. The results show that the segregation of SrO phase on the LSCF surface decreases with the decreasing of temperature. Cr deposition takes place on the LSCF surface after the heat-treatment in the presence of Cr2O3 at temperature range of 700 to 900°C for 48h, forming SrCrO4 phase. As the temperature decreases, less SrCrO4 phase is detected. The surface exchange coefficient of LSCF measured at 900, 800 and 700°C after the heat-treatment in the presence of Cr2O3 for 48h is 1.5×10−4, 1×10−4 and 4×10−5cm s−1, respectively, which is much lower than that measured on the sample tested in the absence of Cr deposition. Chromium poisoning deteriorates the surface exchange and diffusion processes for the O2 reduction reaction on LSCF electrodes. Cr deposition decreases significantly with the decrease of temperature, most likely due to the reduced Sr segregation as well as the decrease of the partial pressure of gaseous Cr species at reduced temperatures.

Effects of Gd and Sr co-doping in CeO2 for electrolyte application in solid oxide fuel cell (SOFC)

Rare earth doped ceria is a key composition for electrolyte application in SOFC. The present trend is to investigate the co-doping approach in ceria either to improve further the electrical conductivity or sintering property. In this study, nano-structured Gd and Sr co-doped ceria (GSDC) powders have been prepared by gel combustion route. In all the compositions, total dopant cation concentration has been kept at 0.20 atom fraction having general formulae Ce0.8Gd0.2−xSrxO1.9−x/2. XRD patterns of GSDC powders calcined at 600°C revealed the phase pure cubic fluorite structure with no Gd2O3 or SrO phase within detection limit. The combustion synthesized powders after sintering at 1350°C resulted in pellets with density more than 96% of theoretical density. The total ionic conductivities have been evaluated from impedance data as a function of temperature in the range of 200–800°C. The results indicate that ionic conductivity increases with small addition (~1mol%) of SrO. At higher SrO concentration ionic conductivity decreases and beyond about 5mol% SrO concentration the ionic conductivity becomes lower than that of CeO2 doped with only Gd2O3. The decrease in ionic conductivity at higher SrO concentration has been attributed to the increase in the enthalpy of oxygen vacancy association. The initial increase in conductivity could be due to scavenging of siliceous phase likely to be present in the grain boundary.

Raman Spectroscopy Study of Chromium Deposition on La0.6Sr0.4Co0.2Fe0.8O3-δ Cathode of Solid Oxide Fuel Cells

Chromium deposition and poisoning is one of the most fundamental issues affecting the performance stability of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) perovskite electrode materials used in intermediate temperature solid oxide fuel cells (IT-SOFCs). In this work, the relationship between the surface segregation, Cr deposition and poisoning is studied using atomic force microscopy (AFM), confocal Raman microscopy and electrical conductivity relaxation method. The results indicate the segregation of SrO and Co3O4 phase on the LSCF surface after heat-treatment at 800°C. After exposed to Cr2O3 at 800°C in dry or wet air for 96 h, Cr deposition on LSCF surface preferentially takes place on the segregated SrO, forming the SrCrO4 phase. Humidity in air accelerates the surface segregation and formation of SrCrO4 on the LSCF surface. The present study provides unambiguous evidences that the segregated SrO plays a vital role in the nucleation and grain growth for the Cr deposition process. Cr deposition significantly deteriorates the surface exchange and diffusion processes for the O2 reduction reaction on LSCF electrodes.

Synthesis and Luminescent Characterization of Sr2SiO4:Eu2+ Nanopowders

Sr2SiO4:Eu2+ nanopowders were synthesized by a co-precipitation method using strontium nitrate, 3-aminopropyltriethoxysilane (APTES), europium nitrate hydrate, and a flux (NH4Cl). The structural and luminescent properties strongly depended on the firing conditions, the amount of APTES, and the flux content. Alpha'-Sr2SiO4 was produced as a dominant phase after firing as-prepared powders without a flux, whereas the addition of NH4Cl caused beta-Sr2SiO4 to be the primary phase. At a small amount of APTES, the as-prepared powders that were fired with NH4Cl consisted of the beta-Sr2SiO4, Sr3SiO5, and un-reacted SrO phases. Then, the phase transformation from SrO and Sr3SiO5 to beta-Sr2SiO4 gradually proceeded as the amount of APTES was increased, leading to the pure beta-Sr2SiO4 phase at 0.5 M APTES. The phase transition and photoluminescence properties strongly relied on the amount of NH4Cl. The preparation condition of 0.5 M APTES and 2 wt% NH4Cl was the optimum condition to obtain the pure beta-Sr2SiO4:Eu2+ phase and the most excellent PL intensity.

Oxygen permeation and stability study of La0.6Sr0.4Co0.8Ga0.2O3−δ (LSCG) hollow fiber membrane with exposure to CO2, CH4 and He

La0.6Sr0.4Co0.8Ga0.2O3−δ (LSCG) perovskite material has been synthesized and fabricated into oxygen permeating hollow fiber membranes. Oxygen permeation from 100mLmin−1 of air at 650°C to 950°C were tested with 100mLmin−1 of pure He, CH4 and CO2 as sweep gases. The maximum O2 permeation flux at 950°C was in the order of CH4 followed by He and CO2 at 7.45mLmin−1cm−2, 3mLmin−1cm−2 and 2.4mLmin−1cm−2. Sweeping with CH4 resulted in the highest flux due to increase in surface exchange reaction whereas the lowest flux was attained for CO2 sweep due to formation of SrCO3. An 80h CO2-stability test was then conducted at 900°C and 800°C. In this CO2-stability study, He and CH4 were intermittently used as sweep gases in order to study their effect on the O2 flux of the CO2 swept LSCG membrane. Interestingly, the fluxes improved upon exposure to He and CH4. However, after being switched back to CO2 from He sweep, the flux slightly improved initially before stabilizing again to the value prior to He sweep. The impact of switching back from CH4 showed insignificant changes in the stabilized flux compared to the initial value. SEM-EDX characterization of the membrane from the CO2-stability study shows considerable erosion at the wall structure with indication of SrCO3, SrO and CoO phases. However, this did not impede the stability of the fluxes or the integrity of the membrane throughout the 80-h study. In fact, XRD shows that the perovskite structure is maintained despite having lower crystallinity.

Thickness-dependent structural phase transition of strained SrRuO3ultrathin films: The role of octahedral tilt

We grew epitaxial SrRuO${}_{3}$ (SRO) films on SrTiO${}_{3}$ (STO) (001) substrates with SRO layer thicknesses ($t$) between 10 and 200 pseudocubic unit cells (uc). Using the square net of the cubic STO surface, we were able to epi-stabilize the tetragonal SRO phase at room temperature for ultrathin films with $t$ \ensuremath{\leqslant} 17 uc. On the other hand thicker films with $t$ \ensuremath{\geqslant} 19 uc have an orthorhombic crystal structure similar to that of bulk SRO at room temperature. With increasing temperature, the orthorhombic films undergo a structural transition to the tetragonal phase at ${T}_{\mathrm{OT}}$. The value of ${T}_{\mathrm{OT}}$ and the orthorhombicity factor at room temperature are reduced with decreasing film thickness. We also observed half-order Bragg reflections, indicating that the tetragonal structure arises from the suppression of the tilt angle of RuO${}_{6}$ octahedra. The observed critical thickness around ${t}_{c}$ \ensuremath{\sim} 18 uc is much larger than the recent theoretical prediction (i.e., less than 2 uc) [J. He, A. Borisevich, S. V. Kalinin, S. J. Pennycook, and S. T. Pantelides, Phys. Rev. Lett. 105, 227203 (2010)]. This work thus demonstrates that the lattice symmetry mismatch at the interface plays an important role in determining the structural properties of perovskite films.

Electrical Properties and Microwave Synthesis of Mixed Rare Earth Oxide Ln 0.7Sr 0.3-x Ca x Co 0.9Fe 0.1 O 3-δ

In order to lower the raw materials cost and develop a novel cathode materials for intermediate temperature solid oxide fuel cell(ITSOFC), using mixed rare earth replacing the expensive pure La 2O 3 as the raw materials, the powders of Ln 0.7Sr 0.3-xCa xCo 0.9Fe 0.1O 3-δ(Ln = the mixed rare earth, x = 0.05, 0.10, 0.15) for the applications as the cathode materials were prepared by microwave sintering process. The crystal structure and the particles morphology of the obtained powders were characterized by XRD and SEM, the electrical conductivity of all samples sintered at 1200 °C for 3 h was also measured as the function of the temperature from 100 to 800 °C by DC four-probe method in air. The experimental results show that due to the influence of mixed rare earth the powders of Ln 0.7Sr 0.3-xCa xCo 0.9Fe 0.1O 3-δ synthesized at 1200 °C for 0.5 h with the mean particle size of 1 ∼ 20 μm was of perovskite and cubic fluorite phase as well a little SrO phase, the electrical conductivity of the samples decreases with the adding Ca 2+ content, and are all higher than 100 S·cm −1 from 500 to 700 °C when x≤0.10. Ln 0.7Sr 0.3-xCa xCo 0.9Fe 0.1O 3-δ. can meet the demand of the electrical properties for the cathode materials in ITSOFC.

A study of interface-sustained ferromagnetism in 1/2( [formula omitted])Ln 2O 3- xSrO/1/3Co 3O 4 nano-composite

The binary oxide composite, consisting of rock salt-type SrO and spinel Co 3O 4 nano-domains, exhibits soft ferromagnetic properties at ambient temperature. This ferromagnetism is originated from interface-induction, and the magnitude of the magnetic properties can be enhanced when the spinel phase of the composite is doped by a small amount of Ln 2O 3 (Ln = La, Nd, for instance). In this work, we study the composites of tri-oxide, 1/2( 1 − x )Ln 2O 3- xSrO/1/3Co 3O 4, where 0.01 ⩽ 1 − x ⩽ 0.6 , by focusing on three areas: (i) generation of nano-composite dominant by interfacial phase via the pyrolysis of preceramic metallo-organic gel; (ii) influence of post-pyrolysis calcination and Ln 2O 3 content on the phase composition of the composite; and (iii) elucidation of different magnetic responses caused by the nature of Ln 2O 3 dissolved in the Co 3O 4 phase. The Ln 3+-doped Co 3O 4 oxide displays only paramagnetic behavior at room temperature, but the ferromagnetic response is attained upon its mixing with SrO in nano-scale. The SrO phase plays the role in assisting Co 3O 4 phase with aligning unpaired electrons through interfacial induction.

Generation of high spin state in the spinel Co 3O 4 nano-domains through interfacial induction

The heterogeneous complex oxide, (1 − x)La– xSr–Co oxides (0.8 ≤ x ≤ 0.99), is observed to possess soft ferromagnetic behaviour at ambient temperature, whereas the corresponding perovskite La 1− x Sr x CoO 3− δ solid solution no longer owns magnetic trait at the same temperature. This complex oxide comprises primarily of spinel Co 3O 4 phase, cubic SrO phase and perovskite La 1− α Sr α CoO 3− β ( α ≪ x) phase. Since both pristine spinel Co 3O 4 and pervoskite structure possess paramagnetic properties at room temperature, the unique ferromagnetic response is interpreted as the result of interfacial induction, presumably through the Jahn–Teller distortion that happened at the octahedral interstices of spinel Co 3O 4 adjacent to the SrO phase. This perspective was further inferred by XRD, ESR and HR-TEM testing. The HR-TEM images exhibit the interpenetrating SrO and Co 3O 4 phases with sizes in nano-scale. The existence of a sufficiently large interface is critical to ensure the induction effect to be detected experimentally. Such an extremely high extent of mixing was attained by pyrolysing the metallo-organic chelating gel containing the above three types of metal ions. Besides the interfacial induction effect, an optimum content of La 2O 3 (1 − x = 0.05) has been verified to play a doping effect, which enhances the response of the spinel Co 3O 4 nano-phase to the interfacial induction.