Fabrication and characterization of high density LaB₆ polycrystalline with (100) preferred orientation

Abstract

High density lanthanum hexaboride (LaB₆) polycrystalline with (100) preferred orientation was prepared by spark plasma sintering (SPS) using LaB₆ nanocubes as raw materials in this work. Microstructure and thermionic electron emission property of LaB₆ polycrystalline were investigated detailedly. The results show that the LaB₆ polycrystalline had a relative density of 95.8%, and there was a (100) preferred orientation on its surface normal to SPS pressing direction. The work function of LaB₆ polycrystalline normal surface was only 2.73 eV, which was almost close to the theoretical work function of LaB₆ (100) single crystal surface. The reasons for preferential orientation of LaB₆ polycrystalline were analyzed.

Keywords

lanthanum hexaboride / spark plasma sintering / microstructure / preferred orientation / work function

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