Magneto-transport properties of a GaMnAs-based ferromagnetic semiconductor trilayer structure grown on a ZnMnSe buffer

• Magneto-transport properties have been investigated in a ferromagnetic GaMnAs/GaAlAs/GaMnAs semiconductor trilayer structure grown on a ZnMnSe buffer layer. The presence of the ZnMnSe buffer leads to the formation of a spin-valve-like structure, which provides the opportunity to investigate spin scattering effects by Hall resistance and magnetoresistance (MR) measurements in the current-in-plane (CIP) configuration. The Curie temperature (T c) and coercivity of the bottom GaMnAs layer are observed to be different from those of the top GaMnAs layer due to the proximity effect between the ferromagnetic GaMnAs and paramagnetic ZnMnSe layers. A two-step behavior is observed in the hysteresis loops of the Hall resistance, indicating that the coercive fields are different in the two GaMnAs layers in the trilayer structure. The magnetoresistance (MR) measured simultaneously with the Hall resistance shows a sudden increase in the field region where the magnetization of the two GaMnAs layers is different. Although the MR ratio was observed to be only 0.04% in our trilayer structure (due to the experimental CIP configuration), the study clearly demonstrates the presence of spin scattering in a trilayer ferromagnetic semiconductor structure grown on a ZnMnSe buffer. © 2008 TMS.

Subject headings

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Keyword

GaMnAs

Proximity effect

TMR

Trilayer

Ferromagnetic semiconductors

Hall resistance

Trilayers

Valve-like structure

Buffer layers

Curie temperature

Ferromagnetic materials

Hall effect

Hysteresis loops

Magnetoresistance

Paramagnetic materials

Semiconductor growth

Semiconducting gallium arsenide

Publication and Content Type

ref (subject category)

art (subject category)