2005/02/23 by Ulrike Lüders, Ulrike Lueders, Manuel Bibès +9 · 2 citations
Materials Science · Physics and Astronomy · #Magnetic Properties and Synthesis of Ferrites #Magnetic properties of thin films #Multiferroics and related materials #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.71.134419
accepted for publication in Phys. Rev. B
arxiv created 2005/02/23 · openalex publication_date 2005/04/25 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Bulk NiFe2O4 is an insulating ferrimagnet. Here, we report on the epitaxial growth of spinel NiFe2O4 ultrathin films onto SrTiO3 single crystals. We will show that---under appropriate growth conditions---epitaxial stabilization leads to the formation of a spinel phase with magnetic and electrical properties that radically differ from those of the bulk material: an enhanced magnetic moment (MS)---about 250% larger---and a metallic character. A systematic study of the thickness dependence of MS allows us to conclude that its enhanced value is due to an anomalous distribution of the Fe and Ni cations among the A and B sites of the spinel structure resulting from the off-equilibrium growth conditions and to interface effects. The relevance of these findings for spinel- and, more generally, oxide-based heterostructures is discussed. We will argue that this novel material could be an alternative ferromagetic-metallic electrode in magnetic tunnel junctions.