TY - JOUR
T1 - Structural properties and thermoelectric performance of the double-filled skutterudite (Sm,Gd)y(FexNi1-x)4Sb12
AU - Artini, Cristina
AU - Carlini, Riccardo
AU - Spotorno, Roberto
AU - Failamani, Fainan
AU - Mori, Takao
AU - Mele, Paolo
N1 - Funding Information:
Cristina Artini and Paolo Mele gratefully thank Shrikant Saini, Atsunori Kamegawa and Toru Kimura of Research Center for Environmentally Friendly Materials Engineering, Muroran Institute of Technology (Muroran, Japan), for providing ball milling facility and giving assistance in the ball milling experiment; Prof. Tsunehiro Takeuchi and Seongho Choi of Toyota Technological Institute (Nagoya, Japan) for providing the samples densification with SPS. This research was funded by CREST, grant number JPMJCR15Q6, and JSPS, grant number KAKENHI JP17H02749.
Funding Information:
Funding: This research was funded by CREST, grant number JPMJCR15Q6, and JSPS, grant number KAKENHI JP17H02749.
Publisher Copyright:
© 2019 by the authors.
PY - 2019/8/1
Y1 - 2019/8/1
N2 - The structural and thermoelectric properties of the filled skutterudite (Sm,Gd)y(FexNi1-x)4 Sb12 were investigated and critically compared to the ones in the Sm-containing system with the aim of unravelling the effect of double filling on filling fraction and thermal conductivity. Several samples (x = 0.50-0.90 and y = 0.15-0.48) were prepared by melting-sintering, and two of them were densified by spark plasma sintering in order to study their thermoelectric features. The crystallographic study enables the recognition of the role of the filler size in ruling the filling fraction and the compositional location of the p/n crossover: It has been found that the former lowers and the latter moves toward lower x values with the reduction of the filler ionic size, as a consequence of the progressively weaker interaction of the filler with the Sb12 cavity. The analysis of thermoelectric properties indicates that, despite the Sm3+/Gd3+ small mass difference, the contemporary presence of these ions in the 2a site significantly affects the thermal conductivity of both p- and n-compositions. This occurs by reducing its value with respect to the Sm-filled compound at each temperature considered, and making the overall thermoelectric performance of the system comparable to several multi-filled (Fe, Ni)-based skutterudites described in the literature.
AB - The structural and thermoelectric properties of the filled skutterudite (Sm,Gd)y(FexNi1-x)4 Sb12 were investigated and critically compared to the ones in the Sm-containing system with the aim of unravelling the effect of double filling on filling fraction and thermal conductivity. Several samples (x = 0.50-0.90 and y = 0.15-0.48) were prepared by melting-sintering, and two of them were densified by spark plasma sintering in order to study their thermoelectric features. The crystallographic study enables the recognition of the role of the filler size in ruling the filling fraction and the compositional location of the p/n crossover: It has been found that the former lowers and the latter moves toward lower x values with the reduction of the filler ionic size, as a consequence of the progressively weaker interaction of the filler with the Sb12 cavity. The analysis of thermoelectric properties indicates that, despite the Sm3+/Gd3+ small mass difference, the contemporary presence of these ions in the 2a site significantly affects the thermal conductivity of both p- and n-compositions. This occurs by reducing its value with respect to the Sm-filled compound at each temperature considered, and making the overall thermoelectric performance of the system comparable to several multi-filled (Fe, Ni)-based skutterudites described in the literature.
KW - Crystal structure
KW - Powder x-ray diffraction
KW - Skutterudites
KW - Thermal conductivity
KW - Thermoelectricity
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U2 - 10.3390/ma12152451
DO - 10.3390/ma12152451
M3 - Article
AN - SCOPUS:85070625384
SN - 1996-1944
VL - 12
JO - Materials
JF - Materials
IS - 15
M1 - 2451
ER -