SrCoO 3−δ thin films by atomic layer deposition

Ahvenniemi, Esko; Matvejeff, M.; Karppinen, Maarit

doi:10.1016/j.apsusc.2014.09.131

Cited by 9 publications

(7 citation statements)

References 34 publications

(45 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, the bulk phase diagram can be used to ascertain which cycle ratio (to tune the composition) and annealing conditions (to tune mixing and phase) need to be employed. In most cases, ALD of a film with the correct stoichiometry does not directly result in a crystalline phase, and a post-deposition anneal is required (this can also be seen in Tables –). ,,,,− ,,,,− ,,,− ,,,,,,,,,,,,,,− Typical annealing conditions are under nitrogen or oxygen atmosphere or in air, and the temperature required to begin crystallization is generally between 600 and 800 °C, with the required temperature often varying depending on the composition of the film. However, while the phase diagram provides thermodynamic information on the bulk system, it has been shown that it often does not rigorously predict the formation of phases in ALD films. , This phenomenon has been hypothesized to be a result of the layer-by-layer growth character of ALD or of bulk material data not applying to the nanometer thickness scale of ALD films, but further investigation is required to unravel the effects.…”

Section: Intermixing and Phase Formationmentioning

confidence: 99%

Synthesis of Doped, Ternary, and Quaternary Materials by Atomic Layer Deposition: A Review

et al. 2018

View full text Add to dashboard Cite

In the past decade, atomic layer deposition (ALD) has become an important thin film deposition technique for applications in nanoelectronics, catalysis, and other areas due to its high conformality on 3-D nanostructured substrates and control of the film thickness at the atomic level. The current applications of ALD primarily involve binary metal oxides, but for new applications there is increasing interest in more complex materials such as doped, ternary, and quaternary materials. This article reviews how these multicomponent materials can be synthesized by ALD, gives an overview of the materials that have been reported in the literature to date, and discusses important challenges. The most commonly employed approach to synthesize these materials is to combine binary ALD cycles in a supercycle, which provides the ability to control the composition of the material by choosing the cycle ratio. Discussion will focus on four main topics: (i) the characteristics, benefits, and drawbacks of the approaches that currently exist for the synthesis of multicomponent materials, with special attention to the supercycle approach; (ii) the trends in precursor choice, process conditions, and characterization methods, as well as underlying motivations for these design decisions; (iii) the distribution of atoms in the deposited material and the formation of specific (crystalline) phases, which is shown to be dependent on the ALD cycle sequence, deposition temperature, and post-deposition anneal conditions; and (iv) the nucleation effects that occur when switching from one binary ALD process to another, with different explanations provided for why the growth characteristics often deviate from what is expected. This paper provides insight into how the deposition conditions (cycle sequence, temperature, etc.) affect the properties of the resultant thin films, which can serve as a guideline for designing new ALD processes. Furthermore, with an extensive discussion on the nucleation effects taking place during the growth of ternary materials, we hope to contribute to a better understanding of the underlying mechanisms of the ALD growth of multicomponent materials.

show abstract

Section: Intermixing and Phase Formationmentioning

confidence: 99%

Synthesis of Doped, Ternary, and Quaternary Materials by Atomic Layer Deposition: A Review

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Further, the oxygen exchange can follow two different isotopic mechanisms, simple hetero-exchange, where only one solid atom participate in the exchange: [6] or multiple hetero-exchange with two solid atoms:…”

Section: Physical Electrical and Electrochemical Characterization-mentioning

confidence: 99%

Electrochemical and Catalytic Properties of Fe-Doped SrCo_0.9-_xNb_0.1Fe_xO_3-δCathode Materials

Cohn

Wang

Pellegrinelli

et al. 2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

Fe and Nb substituted perovskite SrCo 0.9-x Nb 0.1 Fe x O 3-δ (0 < x < 0.3) are investigated as potential cathode materials for intermediate temperature solid oxide fuel cells (SOFCs) and reversible SOFCs (RSOFC). The material's structural stability, electrical conductivity, electrochemical performance and oxygen exchange kinetics were measured. XRD results show improved structural stability of the cubic perovskite structure with Fe doping. A decrease in the electrical conductivity, as well as an increase in the area specific resistance is observed for increasing values of stoichiometric coefficient x. This affect is attributed to limited mobility of oxygen vacancies with the replacement of Co by Fe, as well as to stronger metal-oxygen bonding. The oxygen surface exchange coefficient under different temperatures and oxygen partial pressures was determined. Highest exchange coefficient values were measured with x = 0 Fe doping. The dependence of exchange coefficient on oxygen partial pressure indicates a dissociative adsorption limited process, with participation of molecular oxygen. Activation energies of exchange process were obtained under two different temperature regimes. These results indicate that SrCo 0.9-x Nb 0.1 Fe x O 3-δ (0 < x < 0.3) perovskites maintain their structure at intermediate temperatures and show high catalytic activity toward oxygen reduction, and therefore can serve as potential cathode materials for application in SOFCs and RSOFCs.

show abstract

“…The ORR at the cathode involves a series of complicated processes. The cathodic ORR performance is very much dependent on cathode material, oxygen ion conductivity, electrode thickness, and so on, 16–19 among which the cathode thickness can largely affect the electrocatalytic activity towards ORR via coordination and matching each process of ORR on the porous cathode surface and bulk. Moreover, a certain cathode thickness is needed to effectively avert the reduction of reaction sites and prevent excessive loss of concentration 20–25 …”

Section: Introductionmentioning

confidence: 99%

Thickness‐dependent high‐performance solid oxide fuel cells with Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3‐δ cathode

Qiu

Jiang

Niu

et al. 2022

Asia-Pacific J Chem Eng

View full text Add to dashboard Cite

The electrochemical performance of solid oxide fuel cells (SOFCs) is highly reliant upon the properties of cathodes, including crystal structure, electrical conductivity, electrode thickness, and so on. Here, Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) is synthesized and served as the electrode for enabling highperformance SOFCs. The effect of electrode thickness on the electrocatalytic activity is systematically investigated. The electrode thickness is adjusted in two ways. One is spray-coating and then calcining once, and the other is performing the above process twice. On the basis of symmetrical cells configuration, the oxygen reduction reaction (ORR) activity of BSCF electrode with different thickness is evaluated and analyzed by the electrochemical impedance spectroscopy (EIS) technique and distribution of relaxation time (DRT).The obtained area-specific resistances (ASRs) of electrodes on the oxygen ion conducting electrolyte Sm 0.2 Ce 0.9 O 1.90 (SDC) demonstrate the thicknessdependent electrochemical activity in ORR of BSCF electrode. With an electrode thickness of 24 μm that controlled by conducting "spray-coating and calcining" twice, the BSCF electrode displays the optimal electrochemical performance with an ASR of 0.072 Ω cm 2 in ambient air at 600 C. This strategy has allowed us to produce an electrode layer with optimal thickness, paving a new path for the design of high-performance SOFCs.

show abstract

SrCoO 3−δ thin films by atomic layer deposition

Cited by 9 publications

References 34 publications

Synthesis of Doped, Ternary, and Quaternary Materials by Atomic Layer Deposition: A Review

Synthesis of Doped, Ternary, and Quaternary Materials by Atomic Layer Deposition: A Review

Electrochemical and Catalytic Properties of Fe-Doped SrCo_0.9-_xNb_0.1Fe_xO_3-δCathode Materials

Thickness‐dependent high‐performance solid oxide fuel cells with Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3‐δ cathode

Contact Info

Product

Resources

About

SrCoO 3−δ thin films by atomic layer deposition

Cited by 9 publications

References 34 publications

Synthesis of Doped, Ternary, and Quaternary Materials by Atomic Layer Deposition: A Review

Synthesis of Doped, Ternary, and Quaternary Materials by Atomic Layer Deposition: A Review

Electrochemical and Catalytic Properties of Fe-Doped SrCo0.9-xNb0.1FexO3-δCathode Materials

Thickness‐dependent high‐performance solid oxide fuel cells with Ba0.5Sr0.5Co0.8Fe0.2O3‐δ cathode

Contact Info

Product

Resources

About

Electrochemical and Catalytic Properties of Fe-Doped SrCo_0.9-_xNb_0.1Fe_xO_3-δCathode Materials

Thickness‐dependent high‐performance solid oxide fuel cells with Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3‐δ cathode