酸化物磁石の研究(I) Ba, Sr及びPbフェライトの磁性におよぼすBi₂O₃の影響

抄録

The magnetic properties of Ba-, Sr- and Pb- ferrites with and without Bi₂O₃ were observed. Fe₂O₃ prepared from Fe(CO)₅, BaCO₃, SrCO₃, PbO and Bi₂O₃ were fired at 900° for 2 hours, and then sintered at 1000∼1200° for 15 minutes. The results obtained were as follows: (1) 4πI_s and 4πI_r of Ba-ferrtes with 1.5%Bi₂O₃ were larger than those of Ba-ferrites without Bi₂O₃ by 20∼30% under the above sintering conditions. (2) _IH_C of Ba-ferrites containing Bi₂O₃ was larger than that of single Ba-ferrites by 15∼40% at the composition of Fe₂O₃/BaO<6.0. (3) Such effects of Bi₂O₃ could scarcely be recognized in Sr- and Pb-ferrites. (4) The above effects of Bi₂O₃ might be due to the acceleration of the sintering velocity.