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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

Abstract

(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:
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
OSTI Identifier:
1355407
Report Number(s):
IS-J-9264
Journal ID: ISSN 1359-6454; PII: S1359645417300654
Grant/Contract Number:
NRF-2015R1D1A1A09060920; AC02-07CH11358
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Acta Materialia
Additional Journal Information:
Journal Volume: 128; Journal Issue: C; Journal ID: ISSN 1359-6454
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Gas-atomization; TAGS; Spark plasma sintering; Nanostructures; Mechanical properties

Citation Formats

Kim, Hyo-Seob, Ames Lab., Ames, IA, Dharmaiah, Peyala, Madavali, Babu, Ott, Ryan, Lee, Kap-Ho, and Hong, Soon-Jik. Large-scale production of (GeTe)x (AgSbTe2)100$-$x (x=75, 80, 85, 90) with enhanced thermoelectric properties via gas-atomization and spark plasma sintering. United States: N. p., 2017. Web. doi:10.1016/j.actamat.2017.01.053.
Kim, Hyo-Seob, Ames Lab., Ames, IA, Dharmaiah, Peyala, Madavali, Babu, Ott, Ryan, Lee, Kap-Ho, & Hong, Soon-Jik. Large-scale production of (GeTe)x (AgSbTe2)100$-$x (x=75, 80, 85, 90) with enhanced thermoelectric properties via gas-atomization and spark plasma sintering. United States. doi:10.1016/j.actamat.2017.01.053.
Kim, Hyo-Seob, Ames Lab., Ames, IA, Dharmaiah, Peyala, Madavali, Babu, Ott, Ryan, Lee, Kap-Ho, and Hong, Soon-Jik. Mon . "Large-scale production of (GeTe)x (AgSbTe2)100$-$x (x=75, 80, 85, 90) with enhanced thermoelectric properties via gas-atomization and spark plasma sintering". United States. doi:10.1016/j.actamat.2017.01.053. https://www.osti.gov/servlets/purl/1355407.
@article{osti_1355407,
title = {Large-scale production of (GeTe)x (AgSbTe2)100$-$x (x=75, 80, 85, 90) with enhanced thermoelectric properties via gas-atomization and spark plasma sintering},
author = {Kim, Hyo-Seob and Ames Lab., Ames, IA and Dharmaiah, Peyala and Madavali, Babu and Ott, Ryan and Lee, Kap-Ho and Hong, Soon-Jik},
abstractNote = {(GeTe)x(AgSbTe2)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(AgSbTe2)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 (KIC) of the TAGS-90 sample due to inhibition of dislocation movement at the twin boundary.},
doi = {10.1016/j.actamat.2017.01.053},
journal = {Acta Materialia},
number = C,
volume = 128,
place = {United States},
year = {Mon Jan 30 00:00:00 EST 2017},
month = {Mon Jan 30 00:00:00 EST 2017}
}

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