SEMICONDUCTOR TO TRANSITION IN FeS
| Autor: | A.H. Webster, M.G. Townsend, J.R. Gosselin, R.J. Tremblay |
|---|---|
| Rok vydání: | 1976 |
| Předmět: |
Magnetic moment
Condensed matter physics Chemistry General Engineering Magnetic susceptibility symbols.namesake Electrical resistivity and conductivity Seebeck coefficient symbols Antiferromagnetism Condensed Matter::Strongly Correlated Electrons Electronic band structure Hyperfine structure Debye model |
| Zdroj: | Le Journal de Physique Colloques. 37:C4-11 |
| ISSN: | 0449-1947 |
| DOI: | 10.1051/jphyscol:1976402 |
| Popis: | Summarised here are the conclusions of an investigation by differential thermal analysis, magnetic susceptibility, Mossbauer spectroscopy, electrical conductivity and thermoelectric power on single crystal Fe0.996S. There is an increase in conductivity both parallel and perpendicular to the c-axis by a factor ~ 102 at Tα (~ 420 K). At low temperature the I. S. is characteristic of a non-metal but its temperature dependence appears to be anomalous. Quadrupole hyperfine parameters give some indication of the band structure in the low-temperature (2C) phase. Mossbauer magnetic-hyperfine field data together with the susceptibility results suggest that the magnetic moment does not change significantly at Tα. The Debye temperature, calculated from the Mossbauer fractions, drops significantly at the transition, indicating a lattice contribution to the entropy of transition. We conclude that FeS is a localised-spin antiferromagnet and narrow-band-gap semiconductor below Tα, and a localized-spin antiferromagnet and a not-well-behaved metal above Tα. If the increase in conductivity at Tα arises from delocalization of the 6th s-spin electron, the itinerant electron appears to retain a moment. |
| Databáze: | OpenAIRE |
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