Papers by Keyword: LaGaO₃

Abstract: High-quality La_0.84Sr_0.16Ga_0.26Mg_0.74O_3-δ (LSGM) epitaxial thin films were successfully grown on (100)-SrTiO₃ (STO) substrates at a temperature of 800 °C by a pulsed laser deposition (PLD) method with KrF excimer laser pulses at an ozone pressure of 1.3 × 10³ Pa. X-ray diffraction rocking curve measurements showed that the LSGM films had a full-width at half-maximum (FWHM) value of 0.11 °for out-of-plane 002 reflection, which was smaller than that reported for LaGaO₃ films grown by atomic layer deposition methods (0.18 ^o). The reciprocal spaces mapping of 103 refraction showed that the LSGM films had a slightly larger lattice parameter a (out-of-plane) of 0.393 nm than a_// (in-plane) of 0.391 nm.

Abstract: Solid oxide fuel cells (SOFCs) are electrochemical devices that offer advantages over conventional power generation systems in terms of their high efficiency of power generation, low emission of green house gases and the flexibility of fuel usage. The major research focus of recent times is to lower the operating temperature of SOFC in the range of 600 to 800°C so as to make it commercially viable. This reduction in temperature is largely dependent on finding an electrolyte material with adequate oxygen ion conductivity at the intended operating temperature. One much material is pervoskite LaGaO3 doped with Sr- and Mg- La1-xSrxGa1-yMgyO3-δ (LSGM) that shows very good oxygen ion conductivity at intermediate temperature (600-800°C) over a wide range of oxygen partial pressure. The aim of this overview is to highlight the contribution that materials chemistry has made to the development of LSGM based SOFCs.

Abstract: La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) -based honeycomb cell was first time successfully built and operated in the case of single-wall used condition and the full 4-walls cell one. Power generation characteristic of this honeycomb cell was measured from 700°C to 900°C by using various electrochemical techniques including polarization, current interruption and impedance spectrometry. The LSGM honeycomb cell shows the exact high power density compared with the ZrO2 based cell at the operating temperature range, and its value is 394 and 252 mW/cm2 at 800°C and 700°C, respectively. Thermal stability of this honeycomb cell is also studied and it is seen that the good performance through several times thermal cycling is observed. The 4-walls’s cell stack is successfully working at 800°C, and the volumetric power density is achieved to a value of about 700 mW/cm3.

Abstract: A layer consisting of La0.6Sr0.4CoO3-d particles with inner nano-pores is coated on the La0.7Sr0.3Ga0.6Fe0.4O3-d oxide to improve the surface reaction resulting in high oxygen permeability. The La0.6Sr0.4CoO3-d particles with inner nano-pores are synthesized by an ultrasonic spray pyrolysis method. The permeated oxygen contents from air to helium gas were measured using gas chromatography after the synthesized particles were coated on the La0.7Sr0.3Ga0.6Fe0.4O3-d oxide by the conventional screen-printing. The results demonstrated that the reactive free surfaces of the nano-pores are an important factor in determining the oxygen permeation for application such as gas separation membrane and ceramic fuel cell.

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