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Title: Large-scale production of (GeTe) x (AgSbTe 2) 100$-$x (x=75, 80, 85, 90) with enhanced thermoelectric properties via gas-atomization and spark plasma sintering

(GeTe) x(AgSbTe 2) 100$-$x: TAGS thermoelectrics are an attractive class of materials due to their combination of non-toxicity and good conversion efficiency at mid-temperature ranges. Here in the present work, we have utilized energy and time efficient high-pressure gas atomization and spark-plasma sintering techniques for large-scale preparation of samples with varying composition (i.e., (GeTe) x(AgSbTe 2) 100$-$x where x = 75, 80, 85, and 90). High-temperature x-ray diffraction was used to understand the phase transformation mechanism of the as-atomized powders. Detailed high-resolution transmission electron microscopy of the sintered samples revealed the presence of nanoscale precipitates, antiphase, and twin boundaries. The nanoscale twins and antiphase boundaries serve as phonon scattering centers, leading to the reduction of total thermal conductivity in TAGS-80 and 90 samples. The maximum ZT obtained was 1.56 at 623 K for TAGS-90, which was ~94% improvement compared to values previously reported. The presence of the twin boundaries also resulted in a high fracture toughness (K IC) of the TAGS-90 sample due to inhibition of dislocation movement at the twin boundary.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [3] ;  [4] ;  [1]
  1. Kongju National Univ., Budae-dong, Cheonan, Chungnam (Korea). Division of Advanced Materials Engineering
  2. (United States). Division of Materials Sciences and Engineering
  3. Ames Lab., Ames, IA (United States). Division of Materials Sciences and Engineering
  4. Chungnam National Univ., Daejeon (South Korea). Dept. of Materials Science & Engineering
Publication Date:
Report Number(s):
IS-J-9264
Journal ID: ISSN 1359-6454; PII: S1359645417300654
Grant/Contract Number:
NRF-2015R1D1A1A09060920; AC02-07CH11358
Type:
Accepted Manuscript
Journal Name:
Acta Materialia
Additional Journal Information:
Journal Volume: 128; Journal Issue: C; Journal ID: ISSN 1359-6454
Publisher:
Elsevier
Research Org:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Korean Ministry of Education, Science and Technology
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Gas-atomization; TAGS; Spark plasma sintering; Nanostructures; Mechanical properties
OSTI Identifier:
1355407