Multiferroic and Nanomechanical Properties of Bi1-xGdxFeO3 Polycrystalline Films (x=0.00-0.15)

In this work, we adopted pulsed laser deposition (PLD) with a Nd:YAG laser to develop Bi1-xGdxFeO3 (BGFO) films on glass substrates. The phase composition, microstructure, ferroelectric, magnetic, and nanomechanical properties of BGFO films are studied. BGFO films with x = 0.00-0.15 were confirmed to mainly consist of the perovskite phase. The structure is transformed from rhombohedral for x = 0.00 to pseudo-cubic for x = 0.05-0.10, and an additional phase, orthorhombic, is coexisted for x = 0.15. With increasing Gd content, the microstructure and surface morphology analysis shows a gradual decrease in crystallite size and surface roughness. The hardness of 5.9-8.3 GPa, measured by nanoindentor, is mainly dominated by crystallized structure and grain size. Good ferroelectric properties are found for BGFO films with x = 0.00-0.15, where the largest remanent polarization (2P(r)) of 133.5 mu C/cm(2) is achieved for x = 0.10, related to low leakage and high BGFO(110) texture. The improved magnetic properties with the significant enhancement of saturation magnetization from 4.9 emu/cm(3) for x = 0 to 23.9 emu/cm(3) for x = 0.15 by Gd substitution is found and related to large magnetic moment of Gd3+ and suppressed spiral spin structure of G-type antiferromagnetism. Furthermore, we also discuss the mechanisms of leakage behavior as well as nanomechanical characterizations as a function of the Gd content.

Automated summary

In this work, we used pulsed laser deposition (PLD) with a Nd:YAG laser to fabricate Bi1-xGdxFeO3 (BGFO) films on glass substrates. The study found that with increasing Gd content, there is a gradual decrease in crystallite size and surface roughness in the BGFO films, and the magnetic properties are significantly enhanced due to Gd substitution.