p-type High Temperature Thermoelectric Behavior of Dy Filled CoSb3 and Fe1.5Co2.5Sb12 and Their Magnetic Properties
被引:4
作者:
Dabral, Keshav Prasad
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机构:
Indian Inst Technol, Dept Met Engn & Mat Sci, Mumbai 400076, Maharashtra, IndiaIndian Inst Technol, Dept Met Engn & Mat Sci, Mumbai 400076, Maharashtra, India
Dabral, Keshav Prasad
[1
]
Vitta, Satish
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机构:
Indian Inst Technol, Dept Met Engn & Mat Sci, Mumbai 400076, Maharashtra, IndiaIndian Inst Technol, Dept Met Engn & Mat Sci, Mumbai 400076, Maharashtra, India
Vitta, Satish
[1
]
机构:
[1] Indian Inst Technol, Dept Met Engn & Mat Sci, Mumbai 400076, Maharashtra, India
来源:
ACS APPLIED ENERGY MATERIALS
|
2020年
/
3卷
/
07期
关键词:
p-type skutterudites;
Dy-filling;
Fe substitution;
magnetic behavior;
thermoelectrics;
LATTICE THERMAL-CONDUCTIVITY;
RARE-EARTH;
SKUTTERUDITES;
ENHANCEMENT;
PERFORMANCE;
D O I:
10.1021/acsaem.0c00794
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
Skutterudites are considered to be an ideal choice of material for medium temperature waste heat conversion into usable electrical power. Their inherent electrical transport characteristics together with an option to reduce their thermal conductivity by filling the voids facilitates enhancement of their figure-of-merit zT. Pure CoSb3 with a hole dominant high temperature transport has been found to retain its behavior even after filling the voids with an electron donating ferromagnetic rare-earth Dy. A systematic increase of Dy from 0 to 0.4 is found to increase the maximum value of the Seebeck coefficient from +122 to +146 mu VK-1 for a Dy content of 0.3 before decreasing for 0.4. The electrical conductivity exhibits a degenerate semiconducting behavior with the conductivity decreasing due to Dyfilling. This is due to a decrease in room temperature mobility from 483 to 169 cm(2)V(-1)s(-1), although hole carrier concentration increases slightly. The low temperature magnetic properties of these alloys also show an interesting behavior: diamagnetic to ferromagnetic to paramagnetic transition with increasing Dy-filling. Thermal conductivity on the other hand decreases drastically due to void filling by Dy to a lowest value of 2.7 Wm(-1)K(-1) for 0.3 Dy at 775 K from 3.8 Wm(-1)K(-1) with an enhancement in zT from 0.14 to 0.21, a 50% increase. Partial substitution of Co with Fe in the DyzCo(2.5)Fe(1.5)Sb(12) alloys retains the hole transport behavior, enhances the Dy-filling fraction limit, and also leads to significant improvement in thermoelectric properties. The maximum Seebeck coefficient increases to 155 mu VK-1 while thermal conductivity decreases further to 1.05 Wm(-1)K(-1), the lowest value for a single-filled skutterudite. The corresponding zT increases to 0.67, an increase of similar to 380% compared to Co4Sb12. The Dy-filled Fe-substituted alloys on the other hand show clear ferromagnetic behavior even at room temperature. These studies clearly show that Co or Sb substitution is not essential to have hole transport and that Dy introduces states at the valence band edge, retaining the p-type characteristics.
机构:
Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Bethel Valley Rd, Oak Ridge, TN 37831 USA
Oak Ridge Natl Lab, Computat Sci & Engn Div, Bethel Valley Rd, Oak Ridge, TN 37831 USAClemson Univ, Dept Mech Engn, 201 Fluor Daniel EIB, Clemson, SC 29634 USA
Jakowski, Jacek
Kent, Paul R. C.
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机构:
Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Bethel Valley Rd, Oak Ridge, TN 37831 USA
Oak Ridge Natl Lab, Computat Sci & Engn Div, Bethel Valley Rd, Oak Ridge, TN 37831 USAClemson Univ, Dept Mech Engn, 201 Fluor Daniel EIB, Clemson, SC 29634 USA
Kent, Paul R. C.
Huang, Jingsong
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h-index: 0
机构:
Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Bethel Valley Rd, Oak Ridge, TN 37831 USA
Oak Ridge Natl Lab, Computat Sci & Engn Div, Bethel Valley Rd, Oak Ridge, TN 37831 USAClemson Univ, Dept Mech Engn, 201 Fluor Daniel EIB, Clemson, SC 29634 USA
Huang, Jingsong
Sumpter, Bobby G.
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机构:
Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Bethel Valley Rd, Oak Ridge, TN 37831 USA
Oak Ridge Natl Lab, Computat Sci & Engn Div, Bethel Valley Rd, Oak Ridge, TN 37831 USAClemson Univ, Dept Mech Engn, 201 Fluor Daniel EIB, Clemson, SC 29634 USA
机构:
Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Bethel Valley Rd, Oak Ridge, TN 37831 USA
Oak Ridge Natl Lab, Computat Sci & Engn Div, Bethel Valley Rd, Oak Ridge, TN 37831 USAClemson Univ, Dept Mech Engn, 201 Fluor Daniel EIB, Clemson, SC 29634 USA
Jakowski, Jacek
Kent, Paul R. C.
论文数: 0引用数: 0
h-index: 0
机构:
Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Bethel Valley Rd, Oak Ridge, TN 37831 USA
Oak Ridge Natl Lab, Computat Sci & Engn Div, Bethel Valley Rd, Oak Ridge, TN 37831 USAClemson Univ, Dept Mech Engn, 201 Fluor Daniel EIB, Clemson, SC 29634 USA
Kent, Paul R. C.
Huang, Jingsong
论文数: 0引用数: 0
h-index: 0
机构:
Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Bethel Valley Rd, Oak Ridge, TN 37831 USA
Oak Ridge Natl Lab, Computat Sci & Engn Div, Bethel Valley Rd, Oak Ridge, TN 37831 USAClemson Univ, Dept Mech Engn, 201 Fluor Daniel EIB, Clemson, SC 29634 USA
Huang, Jingsong
Sumpter, Bobby G.
论文数: 0引用数: 0
h-index: 0
机构:
Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Bethel Valley Rd, Oak Ridge, TN 37831 USA
Oak Ridge Natl Lab, Computat Sci & Engn Div, Bethel Valley Rd, Oak Ridge, TN 37831 USAClemson Univ, Dept Mech Engn, 201 Fluor Daniel EIB, Clemson, SC 29634 USA