Coexistence of superconductivity and charge-density wave in the quasi-one-dimensional material HfTe3

Saleem J Denholme,Satoshi Watauchi,Hideaki Takayanagi,Masanori Nagao,Nobuaki Miyakawa,Akinori Yukawa,Kohei Tsumura,Ryuji Tamura,Isao Tanaka

doi:10.1038/srep45217

Saleem J Denholme, Satoshi Watauchi + Show 7 more

Open Access

https://doi.org/10.1038/srep45217

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Abstract

We present the first experimental evidence for metallicity, superconductivity (SC) and the co-existence of charge density waves (CDW) in the quasi-one-dimensional material HfTe3. The existence of such phenomena is a typical characteristic of the transition metal chalcogenides however, without the application of hydrostatic pressure/chemical doping, it is rare for a material to exhibit the co-existence of both states. Materials such as HfTe3 can therefore provide us with a unique insight into the relationship between these multiple ordered states. By improving on the original synthesis conditions, we have successfully synthesised single phase HfTe3 and confirmed the resultant structure by performing Rietveld refinement. Using low temperature resistivity measurements, we provide the first experimental evidence of SC at ~1.4 K as well as a resistive anomaly indicative of a CDW formation at ~82 K. By the application of hydrostatic-pressure, the resistivity anomaly shifts to higher temperature. The results show that HfTe3 is a promising new material to help study the relationship between SC and CDW.

Highlights

Spectroscopy that Hf/HfTe5/HfTe3 films exhibited a superconducting gap-like spectra[22]
On the other hand, when slow cooling was performed until 470 °C after which the ampoules were cooled to room temperature at a rate of approx. −5 °C/h, single phase HfTe3 could reproducibly be synthesised
Studies regarding the electronic structure of HfTe3 are limited, but the issue is briefly reported by Felser et al who determined an electronic structure similar to that of ZrTe3, i.e. a metallic state resulting from a large contribution of the Te p-bands at the Fermi level[16]

Summary

Introduction

Spectroscopy that Hf/HfTe5/HfTe3 films exhibited a superconducting gap-like spectra[22]. HfTe3 and ZrTe3 are iso-structural materials whose features raise the possibility that HfTe3 may exhibit the coexistence of SC and CDW state. The crystal structure has been analyzed using Rietveld refinement and the first experimental evidence of metallicity in this material is reported.

Results

Conclusion