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Title: Large enhancement of Blocking temperature by control of interfacial structures in Pt/NiFe/IrMn/MgO/Pt multilayers

Journal Article · · AIP Advances
DOI:https://doi.org/10.1063/1.4931163· OSTI ID:22492355
; ; ; ; ; ;  [1];  [2];  [3]
  1. Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)
  2. Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China)
  3. Department of Physics, University of Science and Technology Beijing, Beijing 100083 (China)

The Blocking temperature (T{sub B}) of Pt/NiFe/IrMn/MgO/Pt multilayers was greatly enhanced from far below room temperature (RT) to above RT by inserting 1 nm thick Mg layer at IrMn/MgO interface. Furthermore, the exchange bias field (H{sub eb}) was increased as well by the control of interfacial structures. The evidence for a significant fraction of Mn-O bonding at IrMn/MgO interface without Mg insertion layer was provided by X-ray photoelectron spectroscopy. The bonding between Mn and O can decrease the antiferromagnetism of IrMn film, leading to lower value of T{sub B} in Pt/NiFe/IrMn/MgO/Pt multilayers. Ultrathin Mg film inserted at IrMn/MgO interface acting as an oxygen sinking layer can suppress the oxidation reactions between Mn and O and reduce the formation of Mn-O bonding greatly. The oxidation suppression results in the recovery of the antiferromagnetism of IrMn film, which can enhance T{sub B} and H{sub eb}. Furthermore, the high resolution transmission electron microscopy demonstrates that the Mg insertion layer can efficiently promote a high-quality MgO (200) texture. This study will enhance the understanding of physics in antiferromagnet-based spintronic devices.

OSTI ID:
22492355
Journal Information:
AIP Advances, Vol. 5, Issue 9; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
Country of Publication:
United States
Language:
English