Room temperature spin-polarizations of Mn-based antiferromagnetic nanoelectrodes

Journal Article · Mon Nov 03 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4901047· OSTI ID:22391911

Vazquez de Parga, Amadeo L. ^[1]

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1. Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia and Dep. Fisica de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

Antiferromagnets produce no stray field, and therefore, a tip electrode made of antiferromagnetic material has been considered to be the most suitable choice to measure such as magnetoresistance (MR) through single isolated magnetic nanoparticles, molecules, and ultrathin films. Spin polarizations (P) of antiferromagnetic 3-nm, 6-nm, and annealed 3-nm Mn films grown on W tips with a bcc(110) apex as well as bulk-NiMn tips were obtained at 300 K by measuring MR in ultrahigh vacuum by means of spin-polarized scanning tunneling microscopy using a layerwise antiferromagnetically stacking bct-Mn(001) film electrode. The Mn-coated tips with coverages of 3 and 6 nm exhibited P values of 1 ± 1% and 3 ± 2%, respectively, which tips likely contain α- or strained Mn. With a thermal assist, the crystalline quality and the magnetic stability of the film could increase. The annealed tip exhibited P = 9 ± 2%. The bulk-NiMn tips exhibit spin polarizations of 0 or 6 ± 2% probably depending on the chemical species (Mn or Ni) present at the apex of the tip. Fe-coated W tips were used to estimate the bct-Mn(001) film spin polarization.

• OSTI ID: 22391911
• Journal Information: Applied Physics Letters, Vol. 105, Issue 18; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETIC MATERIALS
ANTIFERROMAGNETISM
BCC LATTICES
ELECTRODES
IRON
MAGNETORESISTANCE
MANGANESE
NANOPARTICLES
NANOSTRUCTURES
NICKEL
PHOSPHORUS
SCANNING TUNNELING MICROSCOPY
SPIN ORIENTATION
TEMPERATURE RANGE 0273-0400 K
TETRAGONAL LATTICES
TUNGSTEN