Magnetic ordered states in the oxygen-deficient YBa2(Cu1-xFex)3Oy<6.5 system

✍ Scribed by I.S. Lyubutin; V.G. Terziev; S.V. Luchko; A.Ya. Shapiro; A.M. Balagurov; G.A. Bonch-Osmolovskiy

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 618 KB
• Volume: 199
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(92)90414-8

✦ Synopsis

The magnetically ordered states in the oxygen-deficient YBa2 ( Cut _xFex ) 3Oy ~ 6.~ system (0.01 < x < 0.30) have been studied by MSssbauer spectroscopy. Magnetic ordering of Fe atoms is found at Cu ( 1 ) sites as well as at Cu (2) sites. At small iron concentrations x < 0.05 the Cu ( 1 ) and Cu (2) sublattices are not coupled magnetically and two magnetic phase transitions are observed: the low-temperature transition for the Cu ( 1 ) sublattice at Tm~ ~ 20 K and the high-temperature transition for the Cu (2) sublattice at Tm2 ~ 400 K. With increasing iron concentration at x> 0.10 a strong coupling between the Cu ( 1 ) and Cu (2) sublattices appears and the whole matrix is ordered antiferromagnetically with a single magnetic ordering point Tm2 ~ 460 K. The phase diagrams showing the regions of existence of different magnetic phases versus iron concentration are plotted for the oxygen-saturated and oxygen-reduced YBa2 (Cut -xFex ) 3Oy systems.