TY - JOUR
T1 - Microstructure and thermoelectric properties of Al-doped ZnO ceramic prepared by spark plasma sintering
AU - Radingoana, Precious Manti
AU - Guillemet-Fritsch, Sophie
AU - Noudem, Jacques
AU - Olubambi, Peter Apata
AU - Chevallier, Geoffroy
AU - Estournès, Claude
N1 - Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2023/3
Y1 - 2023/3
N2 - The high thermal and low electrical conductivities of ZnO ceramics have hindered their thermoelectric applications. The doping of ZnO with group 3 elements can enhance the thermoelectric properties. In this work, Al (2 at%) doped ZnO powder was sintered using spark plasma sintering at varying parameters (such as temperature (550–700 ℃), pressure (250–500 MPa) and the temperature of pressure application (Room Temperature (RT) and Holding Time (HT))). Maximum relative density of 98.9% was achieved at a temperature and pressure of 650 °C and 250 MPa, respectively. The Al-doped ZnO ceramics improved in electrical conductivity which caused a decrease in the Seebeck coefficient because of increased carrier concentration. The reduction in the grain size due to inhibiting growth effects of aluminum lead to a decrease in the thermal conductivity through phonon scattering at the grain boundaries. Hence, ZT of 0016 at 500 °C was obtained. This study indicated that Al-doped ZnO ceramics can be sintered at very low temperature of 650 °C. These conditions allow to retain the nanostructure, which is beneficial in improving the thermoelectric properties.
AB - The high thermal and low electrical conductivities of ZnO ceramics have hindered their thermoelectric applications. The doping of ZnO with group 3 elements can enhance the thermoelectric properties. In this work, Al (2 at%) doped ZnO powder was sintered using spark plasma sintering at varying parameters (such as temperature (550–700 ℃), pressure (250–500 MPa) and the temperature of pressure application (Room Temperature (RT) and Holding Time (HT))). Maximum relative density of 98.9% was achieved at a temperature and pressure of 650 °C and 250 MPa, respectively. The Al-doped ZnO ceramics improved in electrical conductivity which caused a decrease in the Seebeck coefficient because of increased carrier concentration. The reduction in the grain size due to inhibiting growth effects of aluminum lead to a decrease in the thermal conductivity through phonon scattering at the grain boundaries. Hence, ZT of 0016 at 500 °C was obtained. This study indicated that Al-doped ZnO ceramics can be sintered at very low temperature of 650 °C. These conditions allow to retain the nanostructure, which is beneficial in improving the thermoelectric properties.
KW - Aluminum
KW - Ceramics
KW - Spark plasma sintering
KW - Thermoelectric properties
KW - ZnO
UR - http://www.scopus.com/inward/record.url?scp=85141292099&partnerID=8YFLogxK
U2 - 10.1016/j.jeurceramsoc.2022.10.034
DO - 10.1016/j.jeurceramsoc.2022.10.034
M3 - Article
AN - SCOPUS:85141292099
SN - 0955-2219
VL - 43
SP - 1009
EP - 1016
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 3
ER -