Abstract
The dibarium scandium aluminum oxide (Ba2ScAlO5) is an important compound for thermionic emission in high-power vacuum devices. Herein, the high-temperature solid-state synthesis mechanism is investigated extensively to develop single-phase <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ba2ScAlO5 and evaluate its emission capacity. Barium carbonate, scandium oxide, and aluminum hydroxide are adopted as the reactants. The synthesis temperature, the intermediate phases, and the cell parameters of the final products differ from sintering the coprecipitated precursor. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ba2ScAlO5 single-phase material can be obtained based on the nonstoichiometric mole ratio of BaO:Sc2O3:Al2O3 = 4.4:1.1:0.9. The X-ray Rietveld refinement reveals that the substitution of Sc for Al and the defects of the Ba, Sc, and O vacancies account for the nonstoichiometry and the shrinkage of cells. The test cathode impregnated with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ba2ScAlO5 doped with Ca2+ exhibits an emission capability of 6.79 A/cm2 at 900 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\circ }\text{C}_{\text {B}}$ </tex-math></inline-formula> in the dc mode. This work demonstrates the feasibility of obtaining <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ba2ScAlO5 with considerable emission through the high-temperature solid-state process.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
