Exploiting B Site Disorder for Phase Control in the Manganites

TL;DR

This paper explores how B site disorder in manganites influences phase control, revealing that dopants can promote specific phases through valence changes or defect creation, and provides a framework for understanding and predicting these phenomena.

Contribution

It introduces a comprehensive framework for understanding B site disorder effects in manganites and predicts new phase-separated states based on dopant behavior.

Findings

B site dopants can promote specific phases via valence change or defect creation.

Analysis explains existing data on phase separation in manganites.

Predictions of highly polarizable phase separated states under certain conditions.

Abstract

Disorder on the active d element site is usually very disruptive for conduction and long range order in perovskite transition metal oxides. However, in the background of phase competition such `B site' dopants also act to promote one ordered phase at the expense of another. This occurs either through valence change of the transition metal or via creation of `defects' in the parent magnetic state. We provide a framework for understanding the complex variety of phenomena observed in B site doped manganites and identify the key parameters that control the physics. Using a spatially resolved analysis of B ions in various manganite phases we explain the existing data and predict new situations where highly polarisable phase separated states can be created.