Modulation of the ferromagnetic insulating phase in Pr0.8Ca0.2MnO3 by Co substitution

TL;DR

This study investigates how Co substitution affects the structural, magnetic, and transport properties of ferromagnetic insulating Pr0.8Ca0.2MnO3 thin films, revealing the roles of double exchange and superexchange interactions.

Contribution

It provides new insights into how Co doping modulates the ferromagnetic insulating phase in Pr0.8Ca0.2MnO3, combining experimental analysis of structural, magnetic, and transport properties.

Findings

Co substitution increases Curie temperature and magnetization up to y=0.3.

Both double exchange and superexchange interactions contribute to ferromagnetic insulating behavior.

Lattice constant variation aligns with Co ions substituting Mn at B-sites.

Abstract

Ferromagnetic insulator Pr0.8Ca0.2Mn1-yCoyO3 (0 <= y <= 0.7) thin films were epitaxially grown on (LaAlO3)0.3-(SrAl0.5Ta0.5O3)0.7 (100) substrates by pulsed laser deposition. To probe the ferromagnetic insulator state of hole-doped manganites, the Co content dependences of the structural, magnetic, and transport properties were studied. Variation of lattice constant by the substitution of Co ions is well reproduced considering that divalent and trivalent Co ions substitute for Mn ions at the perovskite B-sites. For 0 <= y <= 0.3, the Curie temperature, saturation magnetization, and magnetoresistance increase with increasing Co content, retaining the insulating properties. Detailed analyses of transport and magnetic properties indicate the contribution of both double exchange and superexchange interactions to the appearance of the ferromagnetic insulating phase.