New Chemical Method of Obtaining Thick Ga_1-xMn_xN Layers:  Prospective Spintronic Material

Abstract

The synthesis and characterization of Ga 1-x Mn x N thick layers are reported. The layers were prepared by the modified sublimation sandwich method (SSM) from GaN powder and powdered Mn sources and reacted with ammonia. Ga 1-x Mn x N layers having a current maximum size of 60 µm thickness and 10 mm × 10 mm area were obtained. The crystals of best crystalline quality were obtained with a growth rate of 25 µm/h. SIMS measurements showed the presence of layers containing up to 4 atom % Mn. Measurements involving X-ray diffraction (structure refinement), rocking curves, map of reflections, and EXAFS confirmed good structural properties without phase separation. The measurements carried out by a superconducting quantum interferometer showed that the material revealed typical paramagnetic properties.

Antiferromagnetism in Nanofilms of Mn-Doped GaN

“…In this paper, we study Ga 1– x Mn x N unsaturated slabs of 1 nm thickness with wurtzite (WZ) − and zinc-blende (ZB) − crystal structures. We consider the epitaxial growth on a GaN template that, in turn, lies on a substrate typically made of either sapphire, Si, or SiC. , These layers are then doped with two substitutional Mn impurities per unit cell of 128 GaN atoms, the Mn concentration thus being x = 2/64 ≃ 0.03.…”

“…However, more promising nanostructures using (Ga,Mn)N focus on thin films grown on substrates. Although they experimentally show mixed ferromagnetic − and paramagnetic ,− behaviors, we explore here the (Ga,Mn)N nanostructures that besides become antiferromagnetic by decreasing the layer thickness. As this prospect has not yet been observed, it is now timely to investigate the spin coupling trends in (Ga,Mn)N nanofilms, in order to get insights into the magnetism of nitrides.…”

Diffusion of Mn in gallium nitride: Experiment and modelling

“…The second analyzed here phenomenon is Mn out-diffusion from MBE grown samples. Interestingly, this previously disregarded mechanism is ubiquitously observed in (Ga,Mn)N [14,19,24,[31][32][33] as a characteristic a few tens of nm wide drop of Mn concentration observed exclusively near the surface, as exemplified in Figure 3, for the studied here MBE grown layers. The behaviour of a dopant in a foreign material is determined primarily by two quantities: diffusivity and solid solubility.…”

Synthesis of silicon dioxide cone shaped highly ordered hedgehog‐like microstructures on gallium droplets

“…Herein, we report a way to obtain a micrometer sized silicon dioxide “hedgehog”‐like structure on a gallium droplet. The experimental conditions are described in detail in our previous reports . The method of obtaining such ordered structures of SiO 2 presented in this paper seems to be more effective and less complicated.…”