Evidence of lattice strain as a precursor to superconductivity in BaPb0.75Bi0.25O3

M Bharath; Jaskirat Brar; Himanshu Pant; Asif Ali; Sakshi Bansal; Ravi Shankar Singh; R Bindu

doi:10.1088/1361-648X/acabf4

Evidence of lattice strain as a precursor to superconductivity in BaPb_0.75Bi_0.25O₃

J Phys Condens Matter. 2022 Dec 28;35(9). doi: 10.1088/1361-648X/acabf4.

Authors

M Bharath¹, Jaskirat Brar¹, Himanshu Pant¹, Asif Ali², Sakshi Bansal², Ravi Shankar Singh², R Bindu¹

Affiliations

¹ School of Physical Sciences, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh 175005, India.
² Department of Physics, Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh 462066, India.

PMID: 36575860
DOI: 10.1088/1361-648X/acabf4

Abstract

In this work, we have investigated the precursor effects to superconductivity in BaPb_0.75Bi_0.25O₃using temperature dependent resistivity, x-ray diffraction technique and photoemission spectroscopy. The present compound exhibits superconductivity around 11 K (TC). The synthesis procedure adopted is much simpler as compared to the procedure available in the literature. In the temperature range (10 K-25 K) i.e. aboveTC, our results show an increase in both the orthorhombic and tetragonal strain. The well screened features observed in Bi and Pb 4f7/2core levels are indicative of the metallic nature of the sample. The compound exhibits finite intensity at the Fermi level at 300 K and this intensity decreases with decrease in temperature and develops into a pseudogap; the energy dependence of the spectral density of states suggests disordered metallic state. Furthermore, our band structure calculations reveal that the structural transition upon Pb doping results in the closing of the band gap at the Fermi level.

Keywords: bismuthates; doping; lattice distortion; photo electron spectroscopy; superconductivity.