Temperature dependence of charge density wave
ordering in pseudo ternary alloys Er2Ir3-xRhxSi5 as
investigated by transport measurement
P.C. Lalngilneia1*, A. Thamizhavel2, S. Ramakrishnan3 and D. Pal4
2,3
1,4
Department of Physics, Indian Institute of Technology Guwahati, Guwahati-781039, India
Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research,
Mumbai-400005, India
*
Corresponding author’s email: pcmapuia@yahoo.co.in
Abstract
Results
We report the temperature dependence of charge density
wave(CDW) ordering on pseudo-ternary alloys Er2Ir3-xRhxSi5
(where x = 0.01, 0.03, 0.05, 0.08, 0.1) using transport
measurement. We observe that Rh substitution at the Ir site of
Er2Ir3Si5 shows slight increase in CDW transition temperature
as the concentration of Rh increases.
Keywords: Charge Density Wave(CDW), rare-earths intermetallics, phase diagram, phase transition, resistivity.
Introduction
The charge density wave (CDW) transition is a
well-known
quasi-low-dimensional
phenomenon
observed in some conductors [1,2]. Their appearance is
basically due to the nesting of the Fermi surface arising
out of low dimensionality. It has been observed that
among rare-earth ternary silicides of the form R2T3X5
(R = rare-earths; T=Transition elements; X=Si and Ge),
Lu2Ir3Si5 and Er2Ir3Si5 which crystallized in the
U2Co3Si5 type structure (Ibam) exhibit charge density
wave ordering below 200 K[3,4]. The effect of Rh
substitution at Ir site for different Rh concentrations in
polycrystalline Lu2Ir3-xRhxSi5 compounds had also been
studied and a slight increase in TCDW as the Rh
concentration increased was also observed as well [5].
Experimental details
The substituted polycrystalline compounds Er2Ir3xRhxSi5 were made by DC arc-furnace under Ti-gettered
argon atmosphere after the constituent elements(Er, Ir &
Rh = 99.99%, Si = 99.9999%) were taken in
stoichiometric proportion to make around 1g sample.
The resulting ingots were flipped and remelted at least
six times for better homogeneity. The ingots were
wrapped with Zirconium foils and sealed in Quartz tube
and then annealed at 10000C in a furnace for 7 days.
The electrical resistivity measurement, in the
temperature range of 80 K to 300 K, was performed
using four probe dc technique in a homemade setup. For
brevity, the XRD and Rietveld simulated patterns are
not shown here.
Fig. 1: The temperature dependence of the resistivity
for Er2Ir3-xRhxSi5 (where x = 0.01, 0.03, 0.05, 0.08, 0.1)
from 80 K to 300 K showing CDW transitions in the
substituted compounds.
Fig. 2: Plot of TCDW vs Rh concentration (x) for
Er2Ir3-xRhxSi5 (where x = 0.01, 0.03, 0.05, 0.08, 0.1)
References
[1] R. E. Peierls, Quantum Theory of Solids(Oxford
University Press, New York, 1955).
[2] G. Gruner, Density Waves in Solids(AddisonWesley, Reading, MA, 1994)
[3] Yogesh Singh, Dilip Pal, and S. Ramakrishnan, A.
M. Awasthi, and S. K. Malik, Phys. Rev. B 71, 045109
2005.
[4] AIP Conf. Proc. 1447, 1007 (2012).
[5] N. S. Sangeetha,A. Thamizhavel,C. V. Tomy,
Saurabh Basu,A. M. Awasthi,S. Ramakrishnan,and D.
Pal, Phys. Rev. B 86, 024524 (2012).