Control of Microstructures of Sintered Thermoelectric Materials Using Plasma-Treated Powders
Year: 1998
Type: article
Abstract: 糎)吻 〃Z8脱げ亀〃2麗0漉E物毎π》〃〃28π勿1砂5陀〃25 E卿工廠万㎎G解づ即あ5あ001げSO勿π09σ 4 E卿腕βθ7ゴ㎎ ％〃36即 雇0弛勿θ駕ゴ顔乙のθ755-861エ ＊翌)⑳αη｝〃昭鋭(ゾE陀C γゴατ1αフ24E髭C〃07￠名cE㎎∫9￠θθ7∫㎎勲膨Z砂qプ1勉ρ馳θ87∫㎎玲窺卿6勉翫勿θ7Sゴ耽 αり6755」861エ ＊＊耀)砂α7劾￠6π (ゾ漁∫θ露αZSO芸θηα3α 4 Eπ8伽ε〃ゴ㎎Gπτ4κσ忽S漉001 qプSO∫6多2 θσ箆4 E卿腕θβ万㎎ y召η％即。雇翫勿θz師砂，乙の875586エニZ The皿icrostructures at grain boundaries of SiGe， CoSb3 and BiSb(mainly Bi)thermoelectric sintered materials have been controlled by using the plasma-treated raw powders in order to improve their the㎜oelectric properties． The powder surfaces of these materials were treated in the SiH4 plasma for SiGe， the O2 plasma for CoSb3， and the O2， H2， Ar， SbC董3十H2 plasmas for Bi， and their thermoelectric materials were sintered by the spark plasma sinte曲g． For the SiGe samples， the Seebeck coefficient was enhanced by using the SiH4 plasma-treated raw powder， and the result was compared with the calculated one based on the energy filtering effect at Si-rich grain bomdahes． For the CoSb3 samples sintered using the O2 plasma-treated raw powder， a decrease i皿the electrical conduct呈vity and an i皿crease ill the Seebeck coefficient was observed， which were considered to be caused by the energy filtering effect of oxide Iayers at grain boundar量es． The thermal conductivity was decreased． As a result， the figure of merit was improved by using the O2 plasma-treated raw powder． For the Bi samples sintered using the O2 plasma-treated raw powder， the electrical conductivity was increased， suggesting a decrease in the defects at grain boundaries． This result led to an hnprovement in the figure of Inerit． The room temperature values of the figure of merit were in excess of that calculated assuming that Bi single crystal grains are randomly oriented． The Bi samples sintered using other plasma-treated powders had also a higher figure of merit than that of the single crysta1． For BiSb samples sintered using the O2 plasma-treated raw powder， an increase in the electrical conductivity was also observed． (Recelved June 8，1998；In Final Fo㎜August 4，1998) K診〃ωords：魏〃吻0θ惚0誘6御α詑7法α丞ら∫勿詑7認〃3α詑γ毎な，ρ勿∫吻α一舌廻田84ρ0卿鹿7-S∫Z∫00π8召7〃3α擁π翅， α)δα1≠か毎刎勿ZO窺吻，δ空吻％漉α7￠ 勿30フ￠醜，56θゐ66ゐα)顔0∫θπち6あ0 万αZ160ηζ∫％C彦勿∫貌訪6吻αZ COη4％0距加砂，飾θ辮0θ惚0∫万6，㎏％形｛ゾ〃28万
Institution: Yamaguchi University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2605594885