SYNTHESIS AND CHARACTERIZATION OF BA BETA-DIKETONATE COMPLEXES FOR CHEMICAL VAPOR-DEPOSITION OF THIN-FILM SUPERCONDUCTORS

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.