Thermal evolution of the Fe2+–Fe3+ valence mixing in YBaFe2O5 is investigated using Mössbauer spectroscopy. In this high-spin double-cell perovskite, the d6 and d5 Fe states differ by the single minority-spin electron which ...

Oxidation state (OS) is defined using ionic approximation of bonds. Two principal algorithms are outlined for OS determination in a chemical compound described by a Lewis formula or bond graph. Typical origins of ambiguous ...

Magnetoresistance, electrical transport, and magnetic properties associated with a two-step Verwey-type transition in BaGdFe 2 O 5 + w (− 0.015 < w < 0.181 ) are studied as a function of temperature and oxygen nonstoichiometry ...

Two types of chemical-pressure effects on the Verwey-type transition in Ba Sm Fe 2 O 5 are studied, viz., ionic-size contractions at the Ba and Sm sites. Whereas the replacement of Sm by the smaller Eu and Gd atoms increases ...

Pressure effects on the charge-ordering (CO) transition have been investigated for an oxygen-deficient double-perovskite cobalt oxide, BaYCo 2 O 5.0 , through resistivity measurements using a piston-cylinder-type clamp ...

Electronic, magnetic, and structural phase transitions in nearly stoichiometric TbBaFe 2 O 5 + w ( 0.00 < w < 0.05 ) have been investigated. At high temperatures this compound is a paramagnetic, mixed-valence (Fe 2 . 5 + ...

The oxygen-deficient double perovskite YBaCo 2 O 5 , containing corner-linked CoO 5 square pyramids as principal building units, undergoes a paramagnetic to antiferromagnetic spin ordering at 330 K. This is accompanied ...

A mixed-valence state, formally denoted as Fe 2 . 5 + , is observed in the 300 K Mössbauer spectra of the most reduced samples of SmBaFe 2 O 5 + w . Upon cooling below the Verwey-type transition temperature (TV≈ 200 K ) ...

The nuclear and magnetic structures of ( Y 1 − x Ca x ) Ba 2 Fe 3 O 8 + δ with x=0.05, 0.10, and 0.20 have been investigated by neutron-powder diffraction at room temperature. The compound crystallizes with the symmetry ...

© 1994 Acta Chemica Scandinavica

The results of polarized micro-Raman scattering experiments on YBa 2 Fe 3 O 8 + δ with δ=0.1 are reported. We identified seven out of the total ten by symmetry Raman-allowed phonons at 134 cm − 1 ( A 1 g ), 148 cm − 1 ...

© 1993 Acta Chemica Scandinavica

© 1992 Acta Chemica Scandinavica

The nuclear and magnetic structures of YBa 2 Fe 3 O 8 have been investigated by powder neutron diffraction at room temperature. The nuclear structure of the compound has the symmetry of space group P4/mmm and lattice ...

© 1992 Acta Chemica Scandinavica

© 1991 Acta Chemica Scandinavica

© 1991 Acta Chemica Scandinavica

© 1990 Acta Chemica Scandinavica

© 1988 Acta Chemica Scandinavica

© 1988 Acta Chemica Scandinavica

© 1988 Acta Chemica Scandinavica

This research was originally published in Zeitschrift für Kristallographie - New Crystal Structures. © 1988 De Gruyter

© 1987 Acta Chemica Scandinavica