info:eu-repo/semantics/article
Nonstoichiometry driven ferromagnetism in double perovskite La2Ni1-xMn1+ xO6 insulating thin films
Fecha
2019-05Registro en:
Bernal-Salamanca, Monica; Konstantinovic, Zorica; Balcells, Lluis; Pannunzio Miner, Elisa Victoria; Sandiumenge, Felip; et al.; Nonstoichiometry driven ferromagnetism in double perovskite La2Ni1-xMn1+ xO6 insulating thin films; American Chemical Society; Crystal Growth & Design; 19; 5; 5-2019; 2765-2771
1528-7483
CONICET Digital
CONICET
Autor
Bernal-Salamanca, Monica
Konstantinovic, Zorica
Balcells, Lluis
Pannunzio Miner, Elisa Victoria
Sandiumenge, Felip
Lopez Miranda, Laura Ines
Bozzo, Bernat
Herrero Martín, Javier
Pomares, Miguel Alberto
Frontera, Carlos
Martínez, Benjamín
Resumen
In this work we report on the epitaxial growth of La2NiMnO6 double perovskite thin films on top of (001) oriented SrTiO3 substrates by RF magnetron sputtering. The influence of oxygen pressure (P O2) and growth temperature on the microstructure, stoichiometry of the films, and magnetic and transport properties is thoroughly investigated. It is found that high oxygen pressure promotes the growth of stoichiometric films, with a Ni/Mn ratio almost equal to 1. However, these films exhibit poor ferromagnetic properties with respect to the expected optimum values corresponding to ferromagnetic ordering mediated by superexchange interaction between Mn4+ and Ni2+ according to the Goodenough-Kanamori rules. Most interestingly, films grown at low P O2 exhibit Ni/Mn ratios below 1, but ferromagnetic properties close to the optimal ones. The valence balance between Ni and Mn ions in nonstoichiometric sample has been elucidated by X-ray absorption spectroscopy. The results indicate that Ni deficiency plays a crucial role in the puzzling insulating ferromagnetic behavior observed in nonstoichiometric samples.