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Formation and properties of oxide phases in the system Er2O3-Fe2O3

Mixed hydroxide, 3Er(OH)(3)+5Fe(OH)(3) was prepared by chemical coprecipitation. X-Ray diffraction showed that the samples obtained by heating the mixed hydroxide at 650 degrees C were amorphous, and contained Er_2O_3, alpha-Fe_2O_3, ErFeO_3 and Er_3Fe_5O_12 (ErIG) at 750 degrees C. The changes in phase composition of the samples were also monitored by FT-IR spectroscopy. The Mossbauer spectrum of mixed hydroxide, 3Er(OH)(3)+5Fe(OH)(3), at RT was characterized with a quadrupole doublet (delta(Fe)=0.38, Delta=0.80, and Gamma=0.50 mm s(-1)). After heating the starting material up to 650 degrees C, the superposition of two quadrupole doublets and of a sextet of very small intensity with H=506 kOe was observed. This result indicated that the amorphous fraction, as detected by XRD, actually contained additional Fe-bearing oxide phase of very fine particles and probably of poor crystallinity. The sample obtained at 1300 degrees C was characterized by two hyperfine magnetic fields at RT with H-d=394 and H-a=489 kOe corresponding to ErIG. The results of magnetometric measurements of selected samples were discussed. (C) 1997 Elsevier Science S.A. [References: 27]

Oxide-phases. Hydroxides. Iron-garnet. Bismuth. Media. Films

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