Direct proof of unique magnetic and superconducting phases in superoxygenated high-Tc cuprates

TL;DR

This study demonstrates that superoxygenation in La(2-x)Sr(x)CuO(4+y) induces a stable magnetic stripe phase that coexists and separates from superconducting regions, confirmed through neutron scattering and muon spin rotation.

Contribution

It provides the first direct proof that superoxygenation enables magnetic stripe order to emerge and phase separate from superconductivity in high-Tc cuprates.

Findings

Magnetic order appears below T_N ~ T_c = 39 K in all samples.

Magnetic propagation vector and magnetic moment are independent of Sr content.

Superoxygenation induces a magnetic stripe phase distinct from oxygen-stoichiometric La(2-x)Sr(x)CuO(4).

Abstract

We present a combined magnetic neutron scattering and muon spin rotation study of the nature of the magnetic and superconducting phases in electronically phase separated La(2-x)Sr(x)CuO(4+y), x = 0.04, 065, 0.09. For all samples, we find long-range modulated magnetic order below T_N ~ T_c = 39 K. In sharp contrast wit oxygen-stoichiometric La(2-x)Sr(x)CuO(4), we find that the magnetic propagation vector as well as the ordered magnetic moment is independent of Sr content and consistent with that of the 'striped' cuprates. Our study provides direct proof that superoxygenation in La(2-x)Sr(x)CuO(4+y) allows the spin stripe ordered phase to emerge and phase separate from superconducting regions with the hallmarks of optimally doped oxygen-stoichiometric La(2-x)Sr(x)CuO(4).