Phase diagram of charge order in La1.8-xEu0.2SrxCuO4 from resonant soft x-ray diffraction

TL;DR

This study maps the charge order phase diagram in La1.8-xEu0.2SrxCuO4 using resonant soft x-ray diffraction, revealing a charge order dome around x=1/8 that is distinct from other systems, and providing insights into stripe coherence and incommensurability.

Contribution

It presents the first detailed phase diagram of charge ordering in La1.8-xEu0.2SrxCuO4, highlighting a charge order dome independent of structural transitions.

Findings

Charge order dome around x=1/8 detected

Charge order occurs below structural transition temperature

Stripe coherence length and incommensurability vary with Sr concentration

Abstract

Resonant soft x-ray scattering experiments with photon energies near the O K and the Cu L3 edge on the system La1.8-xEu0.2SrxCuO4 for 0.1 <= x <= 0.15 are presented. A phase diagram for stripe-like charge ordering is obtained together with information on the structural transition into the low-temperature tetragonal phase. A clear dome for the charge ordering around x = 1/8 is detected well below the structural transition. This result is quite different from other systems in which static stripes are detected. There the charge order is determined by the structural transition appearing at the same temperature. Furthermore we present results for the coherence length and the incommensurability of the stripe order as a function of Sr concentration.