Redox-driven control of magnetism and structure of polycrystalline PrBaCo2O5+δ

Abstract

Controlling oxygen contents (0.25 ≤ δ ≤ 0.83) and its associated structural and magnetic properties in polycrystalline PrBaCo _2 O _5+ _δ are presented. To control oxygen contents, heat treatments were performed using tube furnace in controlled gas environment. Through temperature dependent reductive annealing, oxygen vacancies are formed in PBCO, and changes of associated properties such as lattice expansion and stabilization of antiferromagnetism are observed. When we performed oxidative annealing, oxygens are intercalated into PBCO. This results in stabilization of ferromagnetism. At last, we checked reversibility through consecutive redox reactions. The structural and magnetic phase transitions occur nearly reversibly. Thus, we could control oxygen contents and associated structural and magnetic properties reversibly through conventional gas reaction.

Keywords

• redox reaction
• oxygen contents
• magnetism