Thermoelectric transport coefficients of n-doped CaTiO3, SrTiO3 and BaTiO3: A theoretical study

2012 ◽  
Vol 407 (7) ◽  
pp. 1114-1118 ◽  
Author(s):  
Rui-zhi Zhang ◽  
Xiao-yun Hu ◽  
Ping Guo ◽  
Chun-lei Wang
1991 ◽  
Vol 234 ◽  
Author(s):  
David J. Bergman ◽  
Ohad Levy

ABSTRACTA theoretical study of composite thermoelectric media has resulted in the development of a number of simple approximations, as well as some exact results. The latter include exact upper and lower bounds on the bulk effective thermoelectric transport coefficients of the composite and upper bounds on the bulk effective thermoelectric quality factor Ze. In particular, as a result of some exact theorems and computer simulations we conclude that Ze can never be greater than the largest value of Z in the different components that make up the composite.


2021 ◽  
Vol 81 (7) ◽  
Author(s):  
He-Xia Zhang ◽  
Jin-Wen Kang ◽  
Ben-Wei Zhang

AbstractThe Seebeck effect and the Nernst effect, which reflect the appearance of electric fields along x-axis and along y-axis ($$E_{x}$$ E x and $$E_{y}$$ E y ), respectively, induced by the thermal gradient along x-axis, are studied in the QGP at an external magnetic field along z-axis. We calculate the associated Seebeck coefficient ($$S_{xx}$$ S xx ) and Nernst signal (N) using the relativistic Boltzmann equation under the relaxation time approximation. In an isotropic QGP, the influences of magnetic field (B) and quark chemical potential ($$\mu _{q}$$ μ q ) on these thermoelectric transport coefficients are investigated. In the presence (absence) of weak magnetic field, we find $$S_{xx}$$ S xx for a fixed $$\mu _{q}$$ μ q is negative (positive) in sign, indicating that the dominant carriers for converting heat gradient to electric field are negatively (positively) charged quarks. The absolute value of $$S_{xx}$$ S xx decreases with increasing temperature. Unlike $$S_{xx}$$ S xx , the sign of N is independent of charge carrier type, and its thermal behavior displays a peak structure. In the presence of strong magnetic field, due to the Landau quantization of transverse motion of (anti-)quarks perpendicular to magnetic field, only the longitudinal Seebeck coefficient ($$S_{zz}$$ S zz ) exists. Our results show that the value of $$S_{zz}$$ S zz at a fixed $$\mu _{q}$$ μ q in the lowest Landau level (LLL) approximation always remains positive. Within the effect of high Landau levels, $$S_{zz}$$ S zz exhibits a thermal structure similar to that in the LLL approximation. As the Landau level increases further, $$S_{zz}$$ S zz decreases and even its sign changes from positive to negative. The computations of these thermoelectric transport coefficients are also extended to a medium with momentum-anisotropy induced by initial spatial expansion as well as strong magnetic field.


Sign in / Sign up

Export Citation Format

Share Document