TY - JOUR
T1 - Physical properties of the full Heusler-type Ru2-xFexNbAl (x = 0.00–0.50) alloys
AU - Bag, P.
AU - Lin, Y. H.
AU - Kuo, Y. K.
AU - Kuo, Chia-Nung
AU - Lue, C. S.
N1 - Funding Information:
This work was supported by the National Science and Technology Council of Taiwan under Grant Nos. NSTC-109–2112-M-006-013 , NSTC-110–2124-M-006-006 , NSTC-110–2124-M-006-010 , and NSTC-109–2112-M-259-007-MY3 (YKK).
Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/6/5
Y1 - 2023/6/5
N2 - We report the physical properties of a series of full Heusler-type Ru2-xFexNbAl (x = 0.00–0.50) alloys using magnetization, electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ) measurements. Structure and phase analysis via x-ray diffraction and scanning electron microscopy indicate that Fe replaces the Ru in Ru2NbAl, and the antisite disorders reduce. The dc magnetization shows predominantly paramagnetic behavior for all Fe-doped samples, as in the pristine Ru2NbAl sample. Interestingly, the electrical resistivity measurements reveal that the conduction behavior of Ru2NbAl alloy changes from semiconducting-like to metal-like with Fe substitution. In addition, a minimum in resistivity at low temperatures is observed in the Fe-doped samples. It is noted that the minimum shifts to low temperatures with Fe content, presumably due to the weak localization effect. The Seebeck coefficient measurements show that charge carriers of these alloys remain hole type with a maximum S value of ∼27 µV/K at 300 K for x = 0.13, a result of the modification of the electronic band structure. The Fe substitution is found to reduce thermal conductivity significantly. An analysis of the lattice thermal conductivity indicates that the reduction in κ is primarily due to more grain boundaries, Umklapp phonons, and electron scatterings. These observations lead to an increase in the thermoelectric performance, i.e., the figure of merit and power factor, to about 0.007 and 1.7 μW/cm K2 at 300 K for the optimized composition of Fe with x = 0.13.
AB - We report the physical properties of a series of full Heusler-type Ru2-xFexNbAl (x = 0.00–0.50) alloys using magnetization, electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ) measurements. Structure and phase analysis via x-ray diffraction and scanning electron microscopy indicate that Fe replaces the Ru in Ru2NbAl, and the antisite disorders reduce. The dc magnetization shows predominantly paramagnetic behavior for all Fe-doped samples, as in the pristine Ru2NbAl sample. Interestingly, the electrical resistivity measurements reveal that the conduction behavior of Ru2NbAl alloy changes from semiconducting-like to metal-like with Fe substitution. In addition, a minimum in resistivity at low temperatures is observed in the Fe-doped samples. It is noted that the minimum shifts to low temperatures with Fe content, presumably due to the weak localization effect. The Seebeck coefficient measurements show that charge carriers of these alloys remain hole type with a maximum S value of ∼27 µV/K at 300 K for x = 0.13, a result of the modification of the electronic band structure. The Fe substitution is found to reduce thermal conductivity significantly. An analysis of the lattice thermal conductivity indicates that the reduction in κ is primarily due to more grain boundaries, Umklapp phonons, and electron scatterings. These observations lead to an increase in the thermoelectric performance, i.e., the figure of merit and power factor, to about 0.007 and 1.7 μW/cm K2 at 300 K for the optimized composition of Fe with x = 0.13.
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U2 - 10.1016/j.jallcom.2023.169318
DO - 10.1016/j.jallcom.2023.169318
M3 - Article
AN - SCOPUS:85148653934
SN - 0925-8388
VL - 945
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
M1 - 169318
ER -