Point defects and thermoelectric properties of iron disilicide ceramics sintered with SiH4‐plasma‐processed micrograins
| Autor: | Toshikatsu Miki, Y. Teraoka, Kengo Kishimoto, Kakuei Matsubara, Y. Matsui, Y. Ebina |
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| Rok vydání: | 1994 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 76:2097-2103 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.357620 |
| Popis: | The point defects in β‐iron disilicide (β‐FeSi2) have been investigated by electron paramagnetic resonance (EPR) along with the thermoelectric properties. The samples used are FeSix (1.9≤x≤2.8) ceramics sintered with FeSix micrograins processed in SiH4‐plasma and nonprocessed. EPR detects (1) several S=1/2 signals and (2) a multiplet signal. An S=1/2 signal with orthorhombic g factors (g1=2.061, g2=2.047, g3=2.024) is detected in all n‐type specimens, and ascribed to unpaired electrons of donors associated with iron vacancies. The other S=1/2 signals are detected in both n‐type and p‐type specimens. The centers responsible for these signals are considered to exist in an oxidized intergrain region of the ceramics. The EPR intensity of the multiplet signal due to the closed‐pair of a high spin Fe3+ ion (S=5/2) and an S=1/2 center is reduced by SiH4‐plasma treatments. SiH4‐plasma processing of FeSix micrograins prior to sintering changes the Seebeck coefficient sign and magnitude, depending upon the conditio... |
| Databáze: | OpenAIRE |
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