Synthesis and Characterization of Ba β-Diketonate Complexes for Chemical Vapor Deposition of Thin-Film Superconductors

Abstract

The synthetic condition and thermal properties of Ba(DPM) 2 (bis-dipivaloylmethanato-barium), Ba(DIVM) 2 (bis-diisovalerylmethanato-barium), and Ba(DBM) 2 (bis-dibutyrylmethanato-barium) were investigated. It was found from NMR analysis that ligands of DPM, DIVM and DBM could be prepared as intended. The yield values of Ba(DIVM) 2 and Ba(DBM) 2 were about three times larger than that of Ba(DPM) 2 . It was clarified from thermal properties measured using thermogravimetry (TG) that volatilization of Ba(DPM) 2 was higher than that of Ba(DIVM) 2 and Ba(DBM) 2 , however, melting points of Ba(DIVM) 2 and Ba(DBM) 2 were slightly lower than that of Ba(DPM) 2 . The volatilization of Ba(DPM) 2 , Ba(DIVM) 2 and Ba(DBM) 2 , exposed to the air for only one week, decreased. The stability of Ba(DPM) 2 (Phen) 2 , Ba(DIVM) 2 (Phen) 2 and Ba(DBM) 2 (Phen) 2 , which were prepared by addition of phenanthroline to Ba(DPM) 2 , Ba(DIVM) 2 and Ba(DBM) 2 , was superior to that of mother barium chelates.