Spin-dependent electron transport in manganite bicrystal junctions
Artikel i vetenskaplig tidskrift, 2012

Magnetic bicrystal films and junctions of magnetic La0.67Sr0.33MnO3 (LSMO) and La0.67Ca0.33MnO3 (LCMO) films epitaxially grown on NdGaO3 substrates with the (110) planes of their two parts misoriented (tilted) at angles of 12A degrees, 22A degrees, 28A degrees, and 38A degrees are investigated. For comparison, bicrystal boundaries with a 90A degrees misorientation of the axes of the NdGaO3 (110) planes were fabricated. The directions of the axes and the magnetic anisotropy constants of the films on both sides of the boundary are determined by two independent techniques of magnetic resonance spectroscopy. The magnetic misorientation of the axes in the substrate plane has been found to be much smaller than the crystallographic misorientation for tilted bicrystal boundaries, while the crystallographic and magnetic misorientation angles coincide for boundaries with rotation of the axes. An increase in the magnetoresistance and characteristic resistance of bicrystal junctions with increasing misorientation angle was observed experimentally. The magnetoresistance of bicrystal junctions has been calculated by taking into account the uniaxial anisotropy, which has allowed the contributions from the tunneling and anisotropic magnetoresistances to be separated. The largest tunneling magnetoresistance was observed on LCMO bicrystal junctions, in which the characteristic resistance of the boundary is higher than that in LSMO boundaries.

magnetic-anisotropy

resistivity

la0.7ca0.3mno3

negative magnetoresistance

grain-boundaries

domain-wall

ferromagnetic-films

la0.67sr0.33mno3 thin-films

low-field magnetoresistance

temperature

Författare

A. M. Petrzhik

National Research University of Electronic Technology (MIET)

V. V. Demidov

National Research University of Electronic Technology (MIET)

Gennady Ovsyannikov

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

I. V. Borisenko

National Research University of Electronic Technology (MIET)

A. V. Shadrin

National Research University of Electronic Technology (MIET)

Chalmers University of Technology

Journal of Experimental and Theoretical Physics

1063-7761 (ISSN) 1090-6509 (eISSN)

Vol. 115 876-884

Ämneskategorier

Fysik

DOI

10.1134/S1063776112100093