TY - GEN
T1 - Thermoelectric properties and their relation to crystal structure of rare earth (RE = La, Nd, Sm and Gd)-doped SrO(SrTiO3)2 Ruddelsden-Popper phase
AU - Wang, Y. F.
AU - Lee, K. H.
AU - Ohta, H.
AU - Koumoto, K.
PY - 2007
Y1 - 2007
N2 - We herein report the significant relaitonship between the thermoelectric properties and the crystallogrphic characteristics, especially the local symmetry of TiO6 octahedra, in the n = 2 Ruddlesden-Popper (RP)-type phases of 5 at.%-rare earth (RE3+ = La3+, Nd3+, Sm3+ and Gd3+)-doped SrO(SrTiO3)2. It was observed that doped RE3+ ions occupied preferentially the Sr-site (CN = 9) in SrO layer, which had a favorable restoration effect on the distorted TiO6 octahedra which was found more effective in smaller-sized RE3+ -doped compounds, as partially proven by the increase in O3-Ti-O3 bond angle with decreasing in ionic radius of RE 3+. The Sm3+ and Gd3+-doped SrO(SrTiO 3)2 exhibited larger Seebeck coefficient (|S|) than those of La3+ and Nd3+-doped SrO(SrTiO3)2 over the whole measured temperature range (300~1000 K). This is considered to be due to the enhancement of the density of states (DOS) in Ti 3d orbitals originated from improved symmetry in TiO6 octahedra by smaller RE3+ doping.
AB - We herein report the significant relaitonship between the thermoelectric properties and the crystallogrphic characteristics, especially the local symmetry of TiO6 octahedra, in the n = 2 Ruddlesden-Popper (RP)-type phases of 5 at.%-rare earth (RE3+ = La3+, Nd3+, Sm3+ and Gd3+)-doped SrO(SrTiO3)2. It was observed that doped RE3+ ions occupied preferentially the Sr-site (CN = 9) in SrO layer, which had a favorable restoration effect on the distorted TiO6 octahedra which was found more effective in smaller-sized RE3+ -doped compounds, as partially proven by the increase in O3-Ti-O3 bond angle with decreasing in ionic radius of RE 3+. The Sm3+ and Gd3+-doped SrO(SrTiO 3)2 exhibited larger Seebeck coefficient (|S|) than those of La3+ and Nd3+-doped SrO(SrTiO3)2 over the whole measured temperature range (300~1000 K). This is considered to be due to the enhancement of the density of states (DOS) in Ti 3d orbitals originated from improved symmetry in TiO6 octahedra by smaller RE3+ doping.
UR - http://www.scopus.com/inward/record.url?scp=51849135504&partnerID=8YFLogxK
U2 - 10.1109/ICT.2007.4569447
DO - 10.1109/ICT.2007.4569447
M3 - 会议稿件
AN - SCOPUS:51849135504
SN - 9781424422623
T3 - International Conference on Thermoelectrics, ICT, Proceedings
SP - 157
EP - 160
BT - Proceedings ICT'07 - 26th International Conference on Thermoelectrics
T2 - ICT'07 - 26th International Conference on Thermoelectrics
Y2 - 3 June 2007 through 7 June 2007
ER -