Open AccessThermoelectric transport properties of Zn-doped n-type Ba8Ga16-2xZnxGe30+x clathrates
Author(s) -
Cong Xiong,
Shukang Deng,
Xinfeng Tang,
Qiong Qi,
Qingjie Zhang
Publication year - 2008
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.57.1190
Subject(s) - spark plasma sintering , materials science , seebeck coefficient , thermoelectric effect , thermal conductivity , electrical resistivity and conductivity , thermoelectric materials , atmospheric temperature range , doping , analytical chemistry (journal) , conductivity , mass fraction , condensed matter physics , sintering , thermodynamics , metallurgy , chemistry , composite material , organic chemistry , physics , optoelectronics , quantum mechanics
The single-phase Zn-doped n-type Ba8Ga16-2xZnxGe30+x clathrates were prepared by melting reaction method combined with spark plasma sintering (SPS). Influences of substituting Zn for Ga on the thermoelectric transport properties of the compounds were investigated. Research results indicate that the electrical conductivity of n-type Ba8Ga16-2xZnxGe30+x compounds increases gradually with the increasing of Zn substitution fraction x. The Seebeck coefficient decreases gradually with the increasing of x. When Zn replaces Ga entirely, the electrical conductivity of Ba8Zn8Ge38 compound drops rapidly and its Seebeck coefficient increases suddenly. Zn substitution fraction x dependence of the thermal conductivity and lattice thermal conductivity are similar in the temperature range from 300 to 1000 K.When xx,lattice thermal conductivity decreases gradually. When x>4, with the increase of x,lattice thermal conductivity increases gradually.In all n_type Ba8Ga16-2xZnxGe30+x clathrates, Ba8Ga8Zn4Ge34 compound has the greatest ZT value, and its maximal ZT value reaches 085 at about 1000K.