TY - JOUR
T1 - Swingback in magnetization reversal in MnAs-GaAs coaxial nanowire heterostructures
AU - Takagaki, Y.
AU - Herfort, J.
AU - Hilse, M.
AU - Geelhaar, L.
AU - Riechert, H.
PY - 2011/3/30
Y1 - 2011/3/30
N2 - The reversal processes of magnetization in epitaxial MnAs nanotubes prepared by an overgrowth on the sidewall of GaAs nanowires having a diameter of 26nm are investigated. While the magnetic hard axis is aligned in the direction of the nanowire axis, we apply an external magnetic field perpendicular to the axis to examine the flipping characteristics of magnetic moments. We determine the contributions from the substrate by a direct measurement in order to extract the magnetization of the core-shell heterostructures. The abrupt change in the thus-obtained magnetization due to a flip when the field is varied exhibits an overshoot at about 0.4kOe for samples with a thickness of the ferromagnetic shell (40-50nm) larger than the diameter of the core. Moreover, the peak value exceeds the value when the field is swept in the opposite direction. The magnetic hysteresis loop consequently involves line crossings. We speculate that the spin textures of domain walls in such thick hollow cylinders and their movement at the magnetization flip are affected by the geometry and magnetostatic interactions of various origins, giving rise to the anomalous behaviour.
AB - The reversal processes of magnetization in epitaxial MnAs nanotubes prepared by an overgrowth on the sidewall of GaAs nanowires having a diameter of 26nm are investigated. While the magnetic hard axis is aligned in the direction of the nanowire axis, we apply an external magnetic field perpendicular to the axis to examine the flipping characteristics of magnetic moments. We determine the contributions from the substrate by a direct measurement in order to extract the magnetization of the core-shell heterostructures. The abrupt change in the thus-obtained magnetization due to a flip when the field is varied exhibits an overshoot at about 0.4kOe for samples with a thickness of the ferromagnetic shell (40-50nm) larger than the diameter of the core. Moreover, the peak value exceeds the value when the field is swept in the opposite direction. The magnetic hysteresis loop consequently involves line crossings. We speculate that the spin textures of domain walls in such thick hollow cylinders and their movement at the magnetization flip are affected by the geometry and magnetostatic interactions of various origins, giving rise to the anomalous behaviour.
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U2 - 10.1088/0953-8984/23/12/126002
DO - 10.1088/0953-8984/23/12/126002
M3 - Article
AN - SCOPUS:79952640205
SN - 0953-8984
VL - 23
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
IS - 12
M1 - 126002
ER -