Mn-Doped GaN

One of the major markets for wide band-gap materials is in electronics. Specifically, they are suitable for and have been used for heat sinks (diamond), short wavelength optoelectronic devices (GaP, GaN, SiC), high-temperature electronics (SiC, GaN), radiation resistant devices, and high-power/high-frequency electronic devices (diamond, GaN, SiC). " Recent research showed that Mn-doped GaN can be used for spintro-nic applications.f" Atomically flat technology developed by NASA for SiC and GaN WBG material can introduce a new dimension of application for WBG materials. 

Table 10.3 Composition of Mn-doped GaN slab, Mn concentration, the energy difference (AE) between the AFM and FM states, the magnetic moment on each Mn atom, the optimized nearest Mn-N bond length ( mh-n) along the [0001] direction, and the optimized Mn-Mn distance (dMn-Mn) for the supercells that are listed in the first column...

With due reverence and deference to the models mentioned above, it is increasingly becoming clear that a true picture can only be obtained by performing first principles calculations. For example, it is stated that the mean-field theory overestimates the critical temperature substantially when the magnetic ion density is small. It has also become dear that in Mn-doped GaN magnetic ion concentration has a profound effect on the way the levels spUt and whether the ferromagnetic or antiferromagnetic state is stable. 

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