52 research outputs found
Metallic and nonmetallic double perovskites: A case study of AFeReO (A= Ca, Sr, Ba)
Full text linkWe have investigated the structure and electronic properties of ferrimagnetic
double perovskites, A2FeReO6 (A= Ca, Sr, Ba). The A=Ba phase is cubic (Fm3m)
and metallic, while the A=Ca phase is monoclinic (P21/n) and nonmetallic.
57Fe Mossbauer spectroscopy shows that iron is present mainly in the
high-spin (S=5/2) Fe3+ state in the Ca compound, while it occurs in an
intermediate state between high-spin Fe2+ and Fe3+ in the Ba compound. It is
argued that a direct Re t2g - Re t2g interaction is the main cause for the
metallic character of the Ba compound; the high covalency of Ca-O bonds and the
monoclinic distortion (which lifts the degeneracy of t2g states) seem to
disrupt the Re-Re interaction in the case of the Ca compound, making it
non-metallic for the same electron count.Comment: 1 eps fil
Highly Active Mixed-Metal Nanosheet Water Oxidation Catalysts Made by Pulsed-Laser Ablation in Liquids
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Simultaneous copper runoff and copper surface analysis in an outdoor area
No full textInternational audienc
Spectroscopic study of oxide layer generated as interface between steel and alumina in plasma spraying process
No full textFT-IR Microscopic Base Imaging System: Applications for Chemical Analysis of Zn and Ni Atmospheric Corrosion
No full textInternational audienc
FT-IR Microscopic Base Imaging System: Applications for Chemical Analysis of Zn and Ni Atmospheric Corrosion
No full textInternational audienc
Non-destructive surface analysis applied to atmospheric corrosion of tin
No full textInternational audienc
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