Magnetization and thermal transport properties of
Nb2Pd0.73S5.7 superconductor
Anil K. Yadav, Anup V. Sanchela and C.V. Tomy
Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai, India – 400076
*
Corresponding author’s e-mail:anilsaciitb@gmail.com, Tel.: +91-02225764552
Abstract
We report the thermal transport properties and figure
of merit (ZT) of newly discovered Nb2Pd0.73S5.7
superconductor. The value of ZT ~ 0.0015 at room
temperature is significant value for a material which
exhibits combined property of superconductivity and
thermoelectric.
temperature that exhibits metallic nature. However,
Seebeck coefficient and correspond figure of merit (ZT)
curves are shown in Fig. 1 (d). The maximum
thermopower ~ 20 μV/K is found about room
temperature. The value of ZT ~ 0.0015 is found at room
temperature.
Keywords: Superconductor, Seebeck coefficient,
Chalcogenide, Figure of merit, thermal transport properties
Introduction
Superconductivity (Tc) ~6.5K is discovered in the nonsuperconducting ternary chalcogenide Nb2Pd0.71Se5
compound when Se is replaced with S [1]. This
superconductor has attracted much to low temperature
research community due to its extremely large upper
critical fields among the known Nb based
superconductors. Here, we reports thermal transport
properties of Nb2Pd0.73S5.7 ingot superconductor.
Experiment Techniques
Polycrystalline sample of Nb2Pd0.73S5.7 is
successfully grown from solid state reaction method.
Magnetization measurement is performed in MPMS
system of Quantum Design (QD). Thermal transport
properties carried out in thermal transport option (TTO)
of physical property measurement system (PPMS) of
QD.
Results and Discussion
The ingot of as grown sample is in the form of
cluster of fiber as shown in SEM image of Fig. 1(a). It
has similar monoclinic crystal structure of Nb2Pd0.71Se5
type belong to C2/m space group [1,2]. The
superconducting transition temperature (Tcon,M , Tcoff,) ~
6.5 K as shown in Fig. 1(b) is reported from
magnetization and electrical transport measurements.
Thermal transport properties are measured via two
probe method between 2 K to 300 K in thermal
transport option of PPMS. Thermal conductivity and
electrical resistivity curves are simultaneously plotted in
Fig. 1 (c). Resistivity decreases with decreaseing
Fig. 1: (a) SEM image of as grown Nb2Pd0.73S5.7 sample.
(b)
Transition
temperature
measured
from
magnetization and electrical measurements at zero field
and Tc mark with arrow. (c) Thermal conductivity
(green) and resistivity (red) at zero field. (d) Seebeck
coefficient (blue) and figure of merit (pink) of
Nb2Pd0.73S5.7 sample.
Acknowledgment
Author wants to acknowledge to Council of Scientific
and Industrial Research (CSIR) for financial support
during PhD.
References
[1] Q. Zhang, G. Li, D. Rhodes, A. Kiswandhi, T.
Besara, B. Zeng, J. Sun, T. Siegrist, M. D. Hohannes, L.
Balicas 3, 1446 (2013).
[2] H. Yu, M. Zuo, L. Zhang, S. Tan, C. Zhang, Y.
Zhang , J. Am. Chem. Soc.135 (35), pp 12987–12989
(2013).