RAER EARTH METAL HEXABORIDE AS ELECTRON EMITTING MATERIAL

摘要

PROBLEM TO BE SOLVED: To obtain an electron emitting material having a long service life and high luminance by using a rare earth metal hexaboride having a compsn. contg. born in excess. SOLUTION: Boron powder is mixed with powder of ReB [where Re is La, Ce or (La+Ce)], this mixture is compacted and the resultant green compact is sintered to obtain a sintered boron-contg. stock rod. This rod is set on the upper shaft of a floating zone growth device through a holder and a sintered rare earth metal hexaboride rod is set on the lower shaft through a holder. The rods are fused by heating, the stock rod is moved upward to form an initial melt zone and the upper and lower shafts are slowly moved downward to obtain the objective rare earth metal hexaboride represented by the formula ReB6-x (where 0.05<=x<=0.20) as an electron emitting material.