Large enhancement of the CDW resistivity anomaly and traces of superconductivity in imperfect samples of NbTe4

Author(s)

de Lima, B. S. ^[1] ; Chaia, N. ^[1] ; Grant, T. W. ^[1] ; de Faria, L. R. ^[1] ; Canova, J. C. ^[1] ; de Oliveira, F. S. ^[1] ; Abud, F. ^[2] ; Machado, A. J. S. ^[1]

Affiliation

^[1] Univ Sao Paulo, Escola Engn Lorena, BR-12600970 Lorena, SP - Brazil

^[2] Univ Sao Paulo, Inst Fis, Rua Matao 1371, BR-05508090 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Materials Chemistry and Physics; v. 226, p. 95-99, MAR 15 2019.
• Web of Science Citations: 1

Abstract

Transition metal chalcogenides usually crystallize in low-dimensional structures that frequently host electronic instabilities such as charge density waves (CDW) and superconductivity. Among them is NbTe4. This compound is a quasi-one-dimensional conductor that exhibits successive CDW transitions and superconductivity at 2.2 K when hydrostatic pressure is applied. The binary Nb-Te phase diagram predicts that this compound is non-stoichiometric and exists within a Te composition range. This work presents a systematic investigation of the physical properties of NbTe4-delta polycrystalline samples. Electrical resistivity measurements show a large enhancement of the anomaly related to the CDW transition in the vicinity of 200 K. Further characterization demonstrates that Te deficiency can also induce superconductivity in this compound at 5.5 K and coexists with the CDW state. (AU)

• FAPESP's process: 16/11774-5 - Study of superconductivity and magnetism in compounds which crystallize on the YbMo2Al4 and IrIn3 prototype structure
• Grantee: Antonio Jefferson da Silva Machado
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/16873-3 - Investigation of new superconductors of the Zr-Cu-Te and Zr-Ni-Te systems
• Grantee: Antonio Jefferson da Silva Machado
• Support Opportunities: Regular Research Grants