Unusual electronic structure ofPrBa2Cu3

R. Fehrenbacher

¹

,

T. M. Rice

²

Abstract

A model for the electronic structure of PrBa2Cu307 is proposed with three independent components: insulating CuC>2 planes with oxidation state Cu 11 , mixed valent Pr ions with almost equal numbers of Pr ,n and Pr IV , and CUO3 chains described by a t-J model with filling ^ 7. The difference from the high-r c superconductors comes from an enhanced stability of the Pr IV state due to the hybridization with O neighbors, and involves a transfer of holes from primarily planar O 2p a to 2p n states. The insulating nature of PrBa2Cu307 is ascribed to the extreme sensitivity of the dc conductivity of the mixed valent Pr ions and the CUO3 chains to vacancies and impurities.

Role ofA-site cations in the metal-insulator transition inPr0.5Ca0.5CoOBarón-González1, Frontera2, García-Muñoz3 et al. 2010Phys. Rev. B385600View full textAdd to dashboardCite

“…This type of hybridization is responsible for the suppression of superconductivity in 123 cuprates with Pr. 31 Hybridization of Bi 6s with O 2p orbitals has been shown to hinder the e g electrons mobility in bismuth-based manganites thus inducing charge order at very high temperatures in these systems ͓up to 600 K ͑Ref. 32͔͒.…”

Resonant tunneling in Y(Dy)Ba2Cu3O7−δ/PrBa2Cu3−xGaxO7−δ/Y(Dy)Ba2Cu3O7−δ ramp-type Josephson junctions

“…is both of fundamental and of practical interest. An unusual electronic structure of this compound was predicted [1,2]. According to these predictions, a strong hybridization of f-states in Pr with p-orbitals of 8 surrounding oxygens takes place [1].…”

Analysis of fluctuation conductivity of polycrystalline Er1-xPr xBa2Cu3O7-δsuperconductors

“…From these studies, it has been observed that increasing Pr substitution in RE 1−x Pr x Ba 2 Cu 3 O 7−δ , causes a monotonically decrease in the critical temperature (T C ) [6]. Some mechanisms such as hole localization [7,8], hole filling [9], magnetic pair breaking [10] and percolation [11] have been proposed to explain the degradation of superconductivity. Also, it was observed an ion-size effect in experiments on the RE 1−x Pr x Ba 2 Cu 3 O 7−δ system for RE = Nd, Eu, Gd, Y, Er and Yb, indicating an approximately linear T C decrease with increasing the RE-site ions radius for a fixed dopant amount x [12].…”