Magnetic properties of Mn‐doped GaN and p ‐ i ‐ n junctions

Abstract

We report on the growth and magnetic properties of GaMnN films and p-i-n junctions grown by metalorganic chemical vapor deposition. The magnetic properties of MOCVD grown GaMnN were found to depend upon the type and concentration of the co-dopant. Si or Mg co-doping of GaMnN films led to either ferromagnetic or paramagnetic behavior depending on the concentration. The magnetic properties within the GaMnN material system appear to correlate with the position of the Fermi level. Ferromagnetism was observed only when the Fermi energy level was within or very close to the Mn energy band. The presence of the Fermi energy level within the Mn energy band allows the presence of carriers that mediate ferromagnetism. These results further confirm that the ferromagnetic properties result from a solid solution of Mn in the GaN. Mn-doped GaN p-i-n junctions which were grown to study the effect of the magnetic properties on the I/V characteristics. These devices consist of GaN:Si/GaMnN/GaN:Mg layers grown by metal-organic chemical vapor deposition. The carrier concentrations for the n and p-type layers are ~ 5x10 18 /cm 3 and 1x10 18/cm 3 respectively, where the GaMnN i layer is approximately 0.2-0.45 µm thick with up to 0.5% Mn.

Selective Growth of Straight and Zigzagged Ga1-xMnxN (0 ≤ x ≤ 0.05) Nanowires and Dependence of Their Electronic Structure and Magnetization on the Mn Content

“…Many previous experimental works have reported on ferromagnetism of p- or n-type films synthesized using various methods (e.g., molecular beam epitaxy, ion implantation, etc. ), attributed to spin-charge double exchange interactions. − Recent theoretical calculations predicted robust ferromagnetism in intrinsic Ga 1- x Mn x N. − On the other hand, there have also been studies that acknowledged the possible presence of some other phases, such as ferromagnetic Mn-rich clusters, due to the low solubility of magnetic ions in GaN. , …”

Growth of bulk Ga(Mn,Si)N single crystals

“…These results are different than these reported in Refs. [5,6] but explanation of these differences exceeds subject area of this work.…”

“…Here we report a method for obtaining free-standing gallium nitride single crystals co-doped with Mn and Si. Properties of Ga(Mn,Si)N were reported earlier by Reed et al [5] and Reed et al [6] but concerned films were grown by MOCVD.…”

The Influence of Mn/Ga Solution Mole Fraction on the Solid Composition and Microstructure of GaN:Mn Thin Film Deposited on Silicon Substrate by Spin Coating Technique

“…For more than thirty years, physicists and engineers are trying to invent a charge transfer device, before spintronic was eventually discovered. Spintronic was then developed into various applications such as spintronic logic device, magnetic random access memory (MRAM), and magnetic field sensor [4,5]. Materials suitable for spintronic devices are the ones having ferromagnetic properties at room temperature and high level of efficiency during spin injection.…”