Abstract

A novel superparamagnetic state has been observed in high quality La0.7Sr0.3MnO3 (LSMO) thin films directly grown by rf-sputtering on SiOx/Si(100) substrates. The films are nanostructured without grain boundaries, constituted by locally epitaxial nanoregions grown layer-by-layer with out-of-plane (012) preferential orientation, induced by the constrain of the native silicon oxide. Low magnetic field ZFC-FC magnetization curves show a cross-over from superparamagnetic to ferromagnetic state dependent of the thickness. The thicker film (140 nm) exhibits typical ferromagnetic order. The thinner films (40 and 60 nm) exhibit superparamagnetic behavior attributed to interacting ferromagnetic monodomain nanoregions with critical size, random in-plane oriented, where the inter-monodomain boundaries with surface spin-glass structure regulate the blocking of magnetization depending on the magnetic field intensity. M(H) hysteresis loops showed noticeable coercive fields in all samples, larger than those reported for LSMO. Such properties of half-metal LSMO film foresee potential integration in new Si-technology nanodevices in Spintronics.

Details

Title
Superparamagnetic state in La0.7Sr0.3MnO3 thin films obtained by rf-sputtering
Author
Ramírez Camacho M C 1 ; Sánchez Valdés C F 2 ; Curiel, M 3 ; Sánchez Llamazares J L 4 ; Siqueiros, J M 5 ; Raymond Herrera O 5 

 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, AP 14, Ensenada, Baja California, México (GRID:grid.9486.3) (ISNI:0000 0001 2159 0001); Instituto de Ingeniería, Universidad Autónoma de Baja California, Mexicali, Blvd. Benito Juarez s/n, Baja California, México (GRID:grid.412852.8) (ISNI:0000 0001 2192 0509) 
 División Multidisciplinaria, Ciudad Universitaria, Universidad Autónoma de Ciudad Juárez, J. J. Macías Delgado # 18100, Ciudad Juárez, Chihuahua, México (GRID:grid.441213.1) 
 Instituto de Ingeniería, Universidad Autónoma de Baja California, Mexicali, Blvd. Benito Juarez s/n, Baja California, México (GRID:grid.412852.8) (ISNI:0000 0001 2192 0509) 
 Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José 2055, Col. Lomas 4ª sección, San Luis Potosí, México (GRID:grid.419262.a) (ISNI:0000 0004 1784 0583) 
 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, AP 14, Ensenada, Baja California, México (GRID:grid.9486.3) (ISNI:0000 0001 2159 0001) 
Publication year
2020
Publication date
2020
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2354710168
Copyright
This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.