Thermoelectric properties of lanthanum sulfide with Sm, Eu, and Yb additives

Journal Article · Fri Apr 01 04:00:00 EST 1988 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.341049· OSTI ID:5374587

Nakahara, J F; Takeshita, T; Tschetter, M J; Beaudry, B J; Gschneidner, Jr, K A

The Seebeck coefficient and electrical resistivity have been measured for the La/sub 3-//sub x/ M/sub x/ S/sub 4/ alloys with the Th/sub 3/ P/sub 4/ -type structure for M = Sm, Eu, Yb, and x = 0.1 to 0.9 in order to determine their potential as high-temperature thermoelectric energy conversion materials. An analysis of the lattice parameters of these alloys suggests that Sm has a valence of 2.2 over the entire composition range. Furthermore, the variation of the Seebeck coefficient and electrical resistivity as a function of electron concentration is different for the Sm-doped alloys than for the Eu- and Yb-doped alloys, which are all different from that of the pure binary LaS/sub y/ alloys. A maximum in the electrical power factor at 1000 /sup 0/C is found to occur at x approx. = 0.3, but when a reasonable estimate is made of the thermal conductivity the maximum in the figure-of-merit at 1000 /sup 0/C shifts to larger x values (approx.0.7) in all alloy systems. The long term stability of the Sm and Eu ternaries is also reported.

• Research Organization: Ames Laboratory, Iowa State University, Ames, Iowa 50011
• OSTI ID: 5374587
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 63:7; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
360603 -- Materials-- Properties
ALLOYS
CONVERSION
DATA
DIRECT ENERGY CONVERSION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRICITY
ENERGY CONVERSION
EUROPIUM ALLOYS
EXPERIMENTAL DATA
INFORMATION
LANTHANUM ALLOYS
NUMERICAL DATA
PHYSICAL PROPERTIES
RARE EARTH ALLOYS
SAMARIUM ALLOYS
SEEBECK EFFECT
SULFUR COMPOUNDS
THERMOELECTRIC CONVERSION
THERMOELECTRIC PROPERTIES
THERMOELECTRICITY
VERY HIGH TEMPERATURE
YTTRIUM ALLOYS