Abstract
| Original language | English |
|---|---|
| Journal | Journal of Materials Science |
| Volume | 54 |
| Issue number | 11 |
| Pages (from-to) | 8482-8491 |
| ISSN | 0022-2461 |
| DOIs | |
| Publication status | Published - 2019 |
Cite this
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Formation mechanism and thermoelectric properties of CaMnO3 thin films synthesized by annealing of Ca0.5Mn0.5O films. / Ekström, Erik; Febvrier, Arnaud le; Fournier, Daniele; Lu, Jun; Ene, Vladimir-Lucian; Nong, Ngo Van; Eriksson, Fredrik; Eklund, Per; Paul, Biplab.
In: Journal of Materials Science, Vol. 54, No. 11, 2019, p. 8482-8491.Research output: Contribution to journal › Journal article › Research › peer-review
TY - JOUR
T1 - Formation mechanism and thermoelectric properties of CaMnO3 thin films synthesized by annealing of Ca0.5Mn0.5O films
AU - Ekström, Erik
AU - Febvrier, Arnaud le
AU - Fournier, Daniele
AU - Lu, Jun
AU - Ene, Vladimir-Lucian
AU - Nong, Ngo Van
AU - Eriksson, Fredrik
AU - Eklund, Per
AU - Paul, Biplab
PY - 2019
Y1 - 2019
N2 - A two-step synthesis approach was utilized to grow CaMnO3 on M-, R- and C-plane sapphire substrates. Radio-frequency reactive magnetron sputtering was used to grow rock-salt-structured (Ca, Mn)O followed by a 3-h annealing step at 800 °C in oxygen flow to form the distorted perovskite phase CaMnO3. The effect of temperature in the post-annealing step was investigated using x-ray diffraction. The phase transformation to CaMnO3 started at 450 °C and was completed at 550 °C. Films grown on R- and C-plane sapphire showed similar structure with a mixed orientation, whereas the film grown on M-plane sapphire was epitaxially grown with an out-of-plane orientation in the [202] direction. The thermoelectric characterization showed that the film grown on M-plane sapphire has about 3.5 times lower resistivity compared to the other films with a resistivity of 0.077 Ωcm at 500 °C. The difference in resistivity is a result from difference in crystal structure, single orientation for M-plane sapphire compared to mixed for R- and C-plane sapphire. The highest absolute Seebeck coefficient value is − 350 µV K−1 for all films and is decreasing with temperature.
AB - A two-step synthesis approach was utilized to grow CaMnO3 on M-, R- and C-plane sapphire substrates. Radio-frequency reactive magnetron sputtering was used to grow rock-salt-structured (Ca, Mn)O followed by a 3-h annealing step at 800 °C in oxygen flow to form the distorted perovskite phase CaMnO3. The effect of temperature in the post-annealing step was investigated using x-ray diffraction. The phase transformation to CaMnO3 started at 450 °C and was completed at 550 °C. Films grown on R- and C-plane sapphire showed similar structure with a mixed orientation, whereas the film grown on M-plane sapphire was epitaxially grown with an out-of-plane orientation in the [202] direction. The thermoelectric characterization showed that the film grown on M-plane sapphire has about 3.5 times lower resistivity compared to the other films with a resistivity of 0.077 Ωcm at 500 °C. The difference in resistivity is a result from difference in crystal structure, single orientation for M-plane sapphire compared to mixed for R- and C-plane sapphire. The highest absolute Seebeck coefficient value is − 350 µV K−1 for all films and is decreasing with temperature.
U2 - 10.1007/s10853-019-03496-7
DO - 10.1007/s10853-019-03496-7
M3 - Journal article
VL - 54
SP - 8482
EP - 8491
JO - Journal of Materials Science
JF - Journal of Materials Science
SN - 0022-2461
IS - 11
ER -