Interplay of the CE-type charge ordering and the A-type spin ordering in a half-doped bilayer manganite La{1}Sr{2}Mn{2}O{7}

TL;DR

This study reveals the coexistence and interplay of CE-type charge ordering and A-type spin ordering in La_{1}Sr_{2}Mn_{2}O_{7}, highlighting their impact on the material's transport properties and phase separation phenomena.

Contribution

It provides new insights into the coexistence of different magnetic and charge orders in a bilayer manganite and their influence on electronic behavior.

Findings

CE-type charge order appears below 210 K with limited volume fraction.

A-type spin order dominates the system.

Coexistence influences transport properties and phase separation.

Abstract

We demonstrate that the half-doped bilayer manganite La_{1}Sr_{2}Mn_{2}O_{7} exhibits CE-type charge-ordered and spin-ordered states below $T_{N, CO}^A = 210$ K and below $T_{N}^{CE} \sim 145$ K, respectively. However, the volume fraction of the CE-type ordering is relatively small, and the system is dominated by the A-type spin ordering. The coexistence of the two types of ordering is essential to understand its transport properties, and we argue that it can be viewed as an effective phase separation between the metallic $d(x^{2}-y^{2})$ orbital ordering and the charge-localized $d(3x^{2}-r^{2})/d(3y^{2}-r^{2})$ orbital ordering.