L10 ordering at different stages of Fe0.5Pd0.5 epitaxial growth
Abstract
FePd layers deposited by molecular beam epitaxy at 620 K on a (001) Pd buffer are investigated. At this growth temperature, an L10 structure is expected; we compare the crystal ordering at different depths in these thin films. 57Fe is used as a local probe at an atomic scale, located at different places within an equimolar FePd layer. The relationship between the alloy structure and the magnetic anisotropy of the films is investigated by Mössbauer spectroscopy. The possible decrease of the L10 ordering during growth is not observed. On the contrary, the quality of the L10 structure seems to improve, as confirmed by the low number of near-neighbors for iron atoms located on the top level of the alloy layer. Iron-rich clusters shaping into large vertical defects across the whole alloy layer are also observed; these clusters correspond to chemically disordered areas within the film. At the buffer interface, disordered, and dilute iron alloys (mean composition: Fe0.25 Pd0.75) with in-plane momenta are identified and explained assuming iron atom diffusion through about 1 nm thick Pd buffer, due to Pd segregation. Some iron rich aggregates could be the consequence of iron homocoordination or Pd surface segregation. The L10 structure is assumed to occur after about 1.7 nm alloy deposit.
- Publication:
-
Journal of Applied Physics
- Pub Date:
- June 2002
- DOI:
- 10.1063/1.1480483
- Bibcode:
- 2002JAP....91.9757H
- Keywords:
-
- iron alloys;
- palladium alloys;
- metallic epitaxial layers;
- molecular beam epitaxial growth;
- crystal structure;
- Mossbauer effect;
- ferromagnetic materials;
- magnetic anisotropy;
- magnetic epitaxial layers;
- surface segregation;
- chemical interdiffusion;
- Anisotropy;
- Crystal Structure;
- Diffusion;
- Epitaxy;
- Ferromagnetic Materials;
- Iron Alloys;
- Magnetic Moments;
- Magnetic Properties;
- Molecular Beam Epitaxy;
- Mossbauer Effect;
- Palladium Alloys;
- Solid-Solid Interfaces;
- Thin Films;
- 68.55.Ac;
- 81.15.Hi;
- 75.50.Bb;
- 68.55.Jk;
- 76.80.+y;
- 75.30.Gw;
- 66.30.Ny;
- 68.35.Fx;
- 75.70.Ak;
- Solid-State Physics;
- Nucleation and growth: microscopic aspects;
- Molecular atomic ion and chemical beam epitaxy;
- Fe and its alloys;
- Structure and morphology;
- thickness;
- crystalline orientation and texture;
- Mossbauer effect;
- other gamma-ray spectroscopy;
- Magnetic anisotropy;
- Chemical interdiffusion;
- diffusion barriers;
- Diffusion;
- interface formation;
- Magnetic properties of monolayers and thin films