In-plane hole density in Ca(0.1)La(0.9)Ba(1.65)La(0.35)Cu(3)O(y) ; nuclear resonance study over the full doping range

TL;DR

This study uses nuclear magnetic resonance to measure in-plane hole density in a series of cuprate samples across the full doping range, revealing saturation in hole density and increased inhomogeneity in overdoped regimes.

Contribution

It provides detailed NMR measurements of in-plane hole density and its fluctuations across the entire doping range in a specific cuprate family, highlighting changes in electronic properties.

Findings

Hole density saturates in overdoped samples

Inhomogeneity increases with doping

Results relate to penetration depth in cuprates

Abstract

We report in-plane Cu(63) Nuclear Magnetic Resonance measurements for a series of fully enriched Ca(0.1)La(0.9)Ba(1.65)La(0.35)Cu(3)O(y) powder samples, which belong to the YBCO family, but the doping could vary from very underdoped to extremely overdoped. From these measurements we determine the average nuclear quadrupole resonance frequency \nu_Q, and its second moment \Delta(\nu_Q), both set by the in-plane hole density, n, as a function of oxygen level, y. We find that in the overdoped side n is saturated, but \Delta(\nu_Q) rapidly increases with increasing y. The relevance of these results to the increasing penetration depth in overdoped cuprates is discussed.