1. Polarized neutron reflectometry from the interface of the heterostructures SiO2(Co)/Si and SiO2(Co)/GaAs
- Author
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D. Lott, Nicolay N. Novitskii, K. Zhernenkov, Boris P. Toperverg, A. I. Stognij, E. A. Dyad’kina, L. V. Lutsev, N. A. Grigoryeva, Maximilian Wolff, Sergey V. Grigoriev, and A. Vorobiev
- Subjects
Materials science ,Condensed matter physics ,Magnetoresistance ,Physics::Optics ,Giant magnetoresistance ,Heterojunction ,Substrate (electronics) ,Atmospheric temperature range ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Condensed Matter Physics ,Computer Science::Other ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Materials Science ,Magnetization ,Ferromagnetism ,Neutron reflectometry ,Electrical and Electronic Engineering - Abstract
Polarized neutron reflectometry is used to investigate SiO2(Co) granular films (70 at% of Co nanoparticles in SiO2 matrix) deposited on Si and GaAs substrates. The aim of the study is to compare magnetization depth profiles in two systems: in SiO2(Co)/GaAs heterostructure which shows at room temperature giant injection magnetoresistance (IMR) with the system SiO2(Co)/Si which reveals almost no IMR effect. We found that at room temperature and at the same value of external magnetic field mean magnetization in the SiO2(Co)/GaAs sample is much higher than in the case of SiO2(Co)/Si. We also demonstrate that magnetic scattering length density, and hence, magnetization profile strongly depends on the substrate. We show that SiO2(Co)/Si heterostructure is ferromagnetically ordered within the temperature range between 120 and 460 K what could explain a weak IMR.
- Published
- 2009
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