Synthesis, Average Structure, and Magnetic Properties of Oxygen Deficient Perovskites (Ba2-3xBi3x-1)(Fe2xBi1-2x)O2+3/2x

A new family of oxygen deficient perovskite [Ba2-3xBi3x-1] [Fe2xBi1-2x]O2+3x/2 has been synthesized for 1/30.45 samples, whose temperatureT spreads from 620 to 720 K. The examination of the paramagnetic domain confirms that iron is trivalent with a high spin configuration (mu=5mu B/Fe3+). The M(H) curve registered at 5 K for x=0.50 shows that this phase is a weak ferromagnet. The magnetic transition is confirmed by calorimetric measurements.