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Anisotropic Magnetoresistance And Planar Hall Effect In Epitaxial Films Of La0.7ca0.3mno3, N. Naftalis, Y. Bason, J. Hoffman, X. Hong, C. H. Ahn, L. Klein
Anisotropic Magnetoresistance And Planar Hall Effect In Epitaxial Films Of La0.7ca0.3mno3, N. Naftalis, Y. Bason, J. Hoffman, X. Hong, C. H. Ahn, L. Klein
Xia Hong Publications
We measured the anisotropic magnetoresistance (AMR) and the planar Hall effect (PHE) in a [001] oriented epitaxial thin film of La0.7Ca0.3MnO3 (LCMO) as a function of magnetic field, temperature, and current direction relative to the crystal axes. We find that both AMR and PHE in LCMO depend strongly on the current orientation relative to the crystal axes, and we demonstrate the applicability of AMR and PHE equations based on a fourth order magnetoresistance tensor consistent with the film symmetry.
High-Mobility Few-Layer Graphene Field Effect Transistors Fabricated On Epitaxial Ferroelectric Gate Oxides, X. Hong, A. Posadas, K. Zou, C. H. Ahn, J. Zhu
High-Mobility Few-Layer Graphene Field Effect Transistors Fabricated On Epitaxial Ferroelectric Gate Oxides, X. Hong, A. Posadas, K. Zou, C. H. Ahn, J. Zhu
Xia Hong Publications
The carrier mobility μ of few-layer graphene (FLG) field-effect transistors increases tenfold when the SiO2 substrate is replaced by single-crystal epitaxial Pb(Zr0.2Ti0:8)O3 (PZT). In the electron-only regime of the FLG, μ reaches 7 X 104 cm2 / Vs at 300 K for n = 2.4 X 1012=cm2, 70% of the intrinsic limit set by longitudinal acoustic (LA) phonons; it increases to 1.4 X 105 cm2 / Vs at low temperature. The temperature-dependent resistivity p(T) reveals a clear signature of LA phonon scattering, yielding …
Quantum Scattering Time And Its Implications On Scattering Sources In Graphene, X. Hong, K. Zou, J. Zhu
Quantum Scattering Time And Its Implications On Scattering Sources In Graphene, X. Hong, K. Zou, J. Zhu
Xia Hong Publications
We determine the quantum scattering time Tq in six graphene samples with mobility of 4 400<μ <17 000 cm2 /V s over a wide range of carrier density (1.2<n<6X1012/cm2). Tq derived from Shubnikov–de Haas oscillation ranges ~25–74 fs, corresponding to a single-particle level broadening of 4.5–13 meV. The ratio of the transport to quantum scattering time Tt /Tq spans 1.5–5.1 in these samples, which can be quantitatively understood combining scattering from short-ranged centers and charged impurities located within 2 nm of the graphene sheet. Our results suggest that charges residing on the SiO …