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Title: Atomic layer deposition of superparamagnetic and ferrimagnetic magnetite thin films

One of the key challenges in realizing superparamagnetism in magnetic thin films lies in finding a low-energy growth way to create sufficiently small grains and magnetic domains which allow the magnetization to randomly and rapidly reverse. In this work, well-defined superparamagnetic and ferrimagnetic Fe{sub 3}O{sub 4} thin films are successfully prepared using atomic layer deposition technique by finely controlling the growth condition and post-annealing process. As-grown Fe{sub 3}O{sub 4} thin films exhibit a conformal surface and poly-crystalline nature with an average grain size of 7 nm, resulting in a superparamagnetic behavior with a blocking temperature of 210 K. After post-annealing in H{sub 2}/Ar at 400 °C, the as-grown α−Fe{sub 2}O{sub 3} sample is reduced to Fe{sub 3}O{sub 4} phase, exhibiting a ferrimagnetic ordering and distinct magnetic shape anisotropy. Atomic layer deposition of magnetite thin films with well-controlled morphology and magnetic properties provides great opportunities for integrating with other order parameters to realize magnetic nano-devices with potential applications in spintronics, electronics, and bio-applications.
Authors:
; ;  [1] ; ;  [2] ;  [1] ;  [3]
  1. Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049 (China)
  2. Energy Systems Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States)
  3. (Canada)
Publication Date:
OSTI Identifier:
22410042
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; CHANNELING; DOMAIN STRUCTURE; FERRITES; GRAIN SIZE; IRON OXIDES; MAGNETIC PROPERTIES; MAGNETITE; MAGNETIZATION; MORPHOLOGY; ORDER PARAMETERS; POTENTIALS; RANDOMNESS; SUPERPARAMAGNETISM; SURFACES; THIN FILMS