Buscar

 Detalle_Publicacion

Interplay between microstructure and magnetism in NiO nanoparticles: Breakdown of the antiferromagnetic order

Abstract: The possibility of tuning the magnetic behaviour of nanostructured 3d transition metal oxides has opened up the path for extensive research activity in the nanoscale world. In this work we report on how the antiferromagnetism of a bulk material can be broken when reducing its size under a given threshold. We combined X-ray diffraction, high-resolution transmission electron microscopy, extended X-ray absorption fine structure and magnetic measurements in order to describe the influence of the microstructure and morphology on the magnetic behaviour of NiO nanoparticles (NPs) with sizes ranging from 2.5 to 9 nm. The present findings reveal that size effects induce surface spin frustration which competes with the expected antiferromagnetic (AFM) order, typical of bulk NiO, giving rise to a threshold size for the AFM phase to nucleate. Ni2+ magnetic moments in 2.5 nm NPs seem to be in a spin glass (SG) state, whereas larger NPs are formed by an uncompensated AFM core with a net magnetic moment surrounded by a SG shell. The coupling at the core-shell interface leads to an exchange bias effect manifested at low temperature as horizontal shifts of the hysteresis loop (~1 kOe) and a coercivity enhancement (~0.2 kOe). © 2014 The Royal Society of Chemistry.

 Autoría: Rinaldi-Montes N., Gorria P., Martínez-Blanco D., Fuertes A., Fernández Barquín L., Rodríguez Fernández J., De Pedro I., Fdez-Gubieda M., Alonso J., Olivi L., Aquilanti G., Blanco J.,

 Fuente: Nanoscale, 2014, 6, 457

Editorial: Royal Society of Chemistry

 Fecha de publicación: 01/01/2014

Nº de páginas: 9

Tipo de publicación: Artículo de Revista

DOI: 10.1039/c3nr03961g

ISSN: 2040-3364,2040-3372

Proyecto español: MAT2011-27573-C04

Url de la publicación: https://doi.org/10.1039/c3nr03961g

Autores/as

RINALDI MONTES, NATALIA MAGDALENA

PEDRO GORRIA KORRES

MARTÍNEZ BLANCO, DAVID

FUERTES ARIAS, ANTONIO BENITO

FERNÁNDEZ GUBIEDA, MARÍA LUISA

ALONSO, JAVIER R.

OLIVI, LUCA

AQUILANTI, GIULIANA

JESUS ANGEL BLANCO RODRIGUEZ