Evidence of Lattice Strain as a Precursor to Superconductivity in BaPb${}_{0.75}$Bi${}_{0.25}$O${}_3$

Abstract

In this work, we have investigated the precursor effects to superconductivity in BaPb${}_{0.75}$Bi${}_{0.25}$O${}_3$ using temperature dependent resistivity, x-ray diffraction technique and photoemission spectroscopy. The present compound exhibits superconductivity around 11 K ($T_C$). 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. above $T_C$, our results show an increase in both the orthorhombic and tetragonal strain. The well screened features observed in Bi and Pb 4$f_{7/2}$ core 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.

References in corpus (7)

• Disorder effects in electronic structure of substituted transition metal compounds
• Momentum-Resolved Electronic Structure of the High-$T_c$ Superconductor Parent Compound BaBiO${}_3$
• Critical test for Altshuler-Aronov theory: Evolution of the density of states singularity in double perovskite Sr${}_2$FeMoO${}_6$ with controlled disorder
• Stripe-like nanoscale structural phase separation and optimal inhomogeneity in superconducting BaPb${}_{1-x}$Bi${}_x$O${}_3$
• Superconductivity-localization interplay and fluctuation magnetoresistance in epitaxial BaPb${}_{1-x}$Bi${}_x$O${}_3$ thin films
• Disorder Driven Metal-Insulator Transition in BaPb${}_{1-x}$Bi${}_x$O${}_3$ and Inference of Disorder-Free Critical Temperature
• Anomalous relaxation kinetics and charge density wave correlations in underdoped BaPb1-xBixO3