Independent Electronic and Magnetic Doping in (Ga,Mn)As Based Digital Ferromagnetic Heterostructures

Abstract

Ferromagnetic semiconductors promise the extension of metal-based spintronics into a material system that combines widely tunable electronic, optical, and magnetic properties. Here, we take steps towards realizing that promise by achieving independent control of electronic doping in the ferromagnetic semiconductor (Ga,Mn)As. Samples are comprised of superlattices of 0.5 monolayer (ML) MnAs alternating with 20 ML GaAs and are grown by low temperature (230 C) atomic layer epitaxy (ALE). This allows for the reduction of excess As incorporation and hence the number of charge-compensating As-related defects. We grow a series of samples with either Be or Si doping in the GaAs spacers (p- and n-type dopants, respectively), and verify their structural quality by in situ reflection high-energy electron diffraction (RHEED) and ex situ x-ray diffraction. Magnetization measurements reveal ferromagnetic behavior over the entire doping range, and show no sign of MnAs precipitates. Finally, magneto-transport shows the giant planar Hall effect and strong (20%) resistance fluctuations that may be related to domain wall motion.

Submitted to Physical Review B. 30 pages, 9 figures

References in corpus (3)

• Effects of annealing time on defect-controlled ferromagnetism in Ga1-xMnxAs
• Spin-polarized Zener tunneling in (Ga,Mn)As
• Ferromagnetic semiconductor (In,Ga,Mn)As with Curie temperature above 100 K

Cited by in corpus (10)

• Ferromagnetic Semiconductors: Moving Beyond (Ga,Mn)As
• Disorder effects in diluted magnetic semiconductors
• Structural, electrical, and magneto-optical characterization of paramagnetic GaMnAs quantum wells
• Revisiting the Mn-doped Ge using the Heyd-Scuseria-Ernzerhof hybrid functional
• Tunable spin polarization in III-V quantum wells with a ferromagnetic barrier
• Post-growth annealing of GaMnAs under As capping - an alternative way to increase Tc
• Evolution of the magnetic anisotropy with carrier density in hydrogenated (Ga,Mn)As
• Electronic structure and exchange constants in magnetic semiconductors digital alloys: chemical and band-gap effects
• The Structure of GaSb Digitally Doped with Mn
• Magnetic susceptibilities of diluted magnetic semiconductors and anomalous Hall-voltage noise