skip to main content

Title: Linear nanometric tunnel junction sensors with exchange pinned sensing layer

Highly sensitive nanosensors with high spatial resolution provide the necessary features for high accuracy imaging of isolated magnetic nanoparticles. In this work, we report the fabrication and characterization of MgO-barrier magnetic tunnel junction nanosensors, with two exchange-pinned electrodes. The perpendicular magnetization configuration for field sensing is set using a two-step annealing process, where the second annealing temperature was optimized to yield patterned sensors responses with improved linearity. The optimized circular nanosensors show sensitivities up to 0.1%/Oe, larger than previously reported for nanometric sensors and comparable to micrometric spin-valves. Our strategy avoids the use of external permanent biasing or demagnetizing fields (large for smaller structures) to achieve a linear response, enabling the control of the linear operation range using only the stack and thus providing a small footprint device.
Authors:
; ;  [1] ;  [2] ; ; ;  [3] ;  [1] ;  [4]
  1. INESC-MN and IN, Rua Alves Redol 9, 1000-029 Lisboa (Portugal)
  2. (IST), Universidade de Lisboa, Av. Rovisco Pais, 1000-029 Lisboa (Portugal)
  3. INL, Av. Mestre Jose Veiga, 4715-31 Braga (Portugal)
  4. (Portugal)
Publication Date:
OSTI Identifier:
22273736
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 17; Conference: 55. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 14-18 Nov 2010; Other Information: (c) 2014 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; 77 NANOSCIENCE AND NANOTECHNOLOGY; ANNEALING; COMPARATIVE EVALUATIONS; FABRICATION; LAYERS; MAGNESIUM OXIDES; MAGNETIZATION; NANOSTRUCTURES; SENSITIVITY; SENSORS; SPATIAL RESOLUTION; SPIN; TUNNEL EFFECT; VALVES