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University of Nebraska - Lincoln

Atomic, Molecular and Optical Physics

2006

Articles 1 - 3 of 3

Full-Text Articles in Physics

Effect Of Electric Field Doping On The Anisotropic Magnetoresistance In Doped Manganites, X. Hong, J. -B. Yau, J. D. Hoffman, C. H. Ahn Jan 2006

Effect Of Electric Field Doping On The Anisotropic Magnetoresistance In Doped Manganites, X. Hong, J. -B. Yau, J. D. Hoffman, C. H. Ahn

Xia Hong Publications

We have modulated the anisotropic magnetoresistance (AMR) in 3–4 nm manganite films using the ferroelectric field effect—a method that electrostatically varies the carrier density without affecting the lattice distortion. While significant changes have been induced in TC and p, the AMR ratio remains the same when the magnetic state is not changed. This scaling behavior is in striking contrast to chemical doping results, where similar modulation of the carrier concentration (~0.1/Mn) changes the AMR ratio by ≥30%. The results reveal unambiguously the dominant role of chemical distortion in determining the AMR in manganites.


Ferromagnetism And Structure Of Epitaxial Cr-Doped Anatase Tio2 Thin Films, T. C. Kaspar, T. Droubay, V. Shutthanandan, S. M. Heald, C. M. Wang, D. E. Mccready, S. Thevuthasan, J. D. Bryan, D. R. Gamelin, A. J. Kellock, M. F. Toney, X. Hong, C. H. Ahn, S. A. Chambers Jan 2006

Ferromagnetism And Structure Of Epitaxial Cr-Doped Anatase Tio2 Thin Films, T. C. Kaspar, T. Droubay, V. Shutthanandan, S. M. Heald, C. M. Wang, D. E. Mccready, S. Thevuthasan, J. D. Bryan, D. R. Gamelin, A. J. Kellock, M. F. Toney, X. Hong, C. H. Ahn, S. A. Chambers

Xia Hong Publications

The materials and magnetic properties of Cr-doped anatase TiO2 thin films deposited on LaAlO3(001) and SrTiO3(001) substrates by oxygen-plasma-assisted molecular beam epitaxy have been studied in detail to elucidate the origin of ferromagnetic ordering. Cr substitution for Ti in the anatase lattice, with no evidence of Cr interstitials, segregation, or secondary phases, was independently confirmed by transmission electron microscopy with energy dispersive x-ray spectroscopy, extended x-ray absorption fine structure, and Rutherford backscattering spectrometry in the channeling geometry. Epitaxial films deposited at ~0.1 Å/ s were found to have a highly defected crystalline structure, as quantified …


Planar Hall-Effect Magnetic Random Access Memory, Y. Bason, L. Klein, J. -B. Yau, X. Hong, J. Hoffman, C. H. Ahn Jan 2006

Planar Hall-Effect Magnetic Random Access Memory, Y. Bason, L. Klein, J. -B. Yau, X. Hong, J. Hoffman, C. H. Ahn

Xia Hong Publications

We suggest a type of magnetic random access memory (MRAM) that is based on the phenomenon of the planar Hall effect (PHE) in magnetic films, and we demonstrate this idea with manganite films. The PHE-MRAM is structurally simpler than the currently developed MRAM that is based on magnetoresistance tunnel junctions, with the tunnel junction structure being replaced by a single-layer film.