Impregnating electrical and magnetic oxide ceramics with fluorine - to obtain partial reaction and varying properties

摘要

Oxide materials such as ferrimagnetics and ferroelectrics are fluorisides by diffusing F2 or a fluoride gas at a temp. slightly above ambient but below the temp. of formation of the material and at a pressure close to atmospheric, into the preformed and partially sintered material. Oxyfluoride compsns. are produced. Introduction of fluoride into the ceramics by diffusion provides variations of the properties and parameters of the material throughout its thickness. The process is specifically applied to ferroelectric and ferrite bodies. The fluorine (cpd.) is pref. diffused into an enclosure in which a secondary vacuum has been previously produced, at about 400 degrees C for 1-10h., and 3-4 times atmospheric pressure. After diffusion, the material is pref. cooled in a known cooling device, so that the amt. of fluorine absorbed can be calculated.