Back to Search
Start Over
Metal-semiconductor-transition observed in Bi2Ca(Sr, Ba)2Co2O8+δ single crystals.
- Source :
- Applied Physics Letters; 7/28/2014, Vol. 105 Issue 4, p1-5, 5p, 5 Graphs
- Publication Year :
- 2014
-
Abstract
- Electrical property evolution of Bi<subscript>2</subscript>AE<subscript>2</subscript>Co<subscript>2</subscript>O<subscript>8+δ</subscript> single crystals (AE = Ca, Sr and Ba) is systematically explored. When AE changes from Ca to Ba, the electrical property of Bi<subscript>2</subscript>Ca<subscript>2</subscript>Co<subscript>2</subscript>O<subscript>8+δ</subscript> and Bi<subscript>2</subscript>Sr<subscript>2</subscript>Co<subscript>2</subscript>O<subscript>8+δ</subscript> demonstrates semiconductor-like properties. But Bi<subscript>2</subscript>Ba<subscript>2</subscript>Co<subscript>2</subscript>O<subscript>8+δ</subscript> shows the metallic behavior. Analysis of temperature-dependent resistance substantiates that from metallic Bi<subscript>2</subscript>Ba<subscript>2</subscript>Co<subscript>2</subscript>O<subscript>8+δ</subscript> to semiconductor-like Bi<subscript>2</subscript>Sr<subscript>2</subscript>Co<subscript>2</subscript>O<subscript>8+δ</subscript> can be attributed to Anderson localization. However the semiconductor behaviour of Bi<subscript>2</subscript>Sr<subscript>2</subscript>Co<subscript>2</subscript>O<subscript>8+δ</subscript> and Bi<subscript>2</subscript>Ca<subscript>2</subscript>Co<subscript>2</subscript>O<subscript>8+δ</subscript> is related to electronic correlations effect that is inferred by large negative magnetoresistance (70%). The theoretical electronic structures and valence X-ray photoemission spectroscopy substantiate that there is a relative large density of state around Fermi level in Bi<subscript>2</subscript>Ba<subscript>2</subscript>Co<subscript>2</subscript>O<subscript>8+δ</subscript> compared with other two compounds. It suggests that Bi<subscript>2</subscript>Ba<subscript>2</subscript>Co<subscript>2</subscript>O<subscript>8+δ</subscript> is more apt to be metal in this material system. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00036951
- Volume :
- 105
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Applied Physics Letters
- Publication Type :
- Academic Journal
- Accession number :
- 97347383
- Full Text :
- https://doi.org/10.1063/1.4891845