Electrical properties of Ce0.85Sm0.15O1.925–Fe2O3 electrolytes for IT-SOFCs

In situ ambient pressure XPS observation of surface chemistry and electronic structure of α-Fe2O3 and γ-Fe2O3 nanoparticles

“…Iron (III) oxides, in their most thermodynamically stable polymorphic phase of hematite (α-Fe 2 O 3 ) and metastable maghemite (γ-Fe 2 O 3 ), are intriguing semiconducting materials among other transition metal oxides, which are used i.a. in solar energy conversion devices and water splitting [7], heterogeneous catalysis including also photocatalysis [8], in fuel cells [9] and gas sensing applications [10]. They are narrow band gap semiconductors within the range of 1.8 -2.2 eV (depending on their synthesis and processing), chemically stable, exhibiting interesting magnetic and optical behavior.…”

Structural and electrical properties of geopolymer materials based on different precursors (kaolin, bentonite and diatomite)

“…In our work, the original Nyquist plots [18] were recorded in the available frequency range (1 Hz -100 kHz). The high-frequency semicircle may be attributed to a parallel connection of the bulk resistance (Rb) of crystallite grains and the geometric capacitance (Cg) of the sample.…”

“…Generally, the impedance spec-tra are presented as the negative of the imaginary component of impedance (-Zimag) versus the real component of impedance (Zreal) (i.e., as a Nyquist plot). A typical Nyquist plot of an electrolyte in solid state consists of three semicircles, where semicircles at high and intermediate frequencies are ascribed to the bulk and grain boundaries, while a semicircle at low frequency represents the electrode process contribution [18]. For high and intermediate frequency semicircles, two serially connected RC circuits are characteristic, and both of these contain one resistive and one capacitive element bonded in a parallel arrangement, the capacitive element being a distributed (frequency dependent) one.…”

Improved performance of a samarium-doped ceria interlayer of intermediate temperature solid oxide electrolysis cells by doping the transition metal oxide Fe2O3

“…Since the interlayer can not only inhibit the diffusion of Sr but also act as a bridge to transport oxygen ions from the electrolyte to the oxygen electrode, the interlayer performance can be improved by increasing its density and oxygen ion conduction. It is reported that the transition metal oxide Fe 2 O 3 can play the role of a sintering aid and grain boundary cleaning agent for the doped ceria electrolyte, [20][21][22][23][24] so doping Fe 2 O 3 can improve the density and oxygen ion conduction of the doped ceria interlayer. Based on this, this work will study the effect of the transition metal oxide Fe 2 O 3 on the performance of a samarium-doped ceria (SDC) interlayer of IT-SOECs.…”