Semiconductor Characteristic and Ferromagnetism in Rare Earth (Eu, Er)-Doped AlGaN Alloy: LSDA + U Approach

Theoretical Investigation of Physical Properties of Eu and Er co-doped AlGaN Alloy

“…Our ndings, as presented in Table 2, indicate that the majority of the magnetic moment is highly localized on the Eu (5.90 µ B ) and Er (2.99 µ B ) sites, which is consistent with Eu and Er-doped InGaN alloy [31,32]. However, this value is higher than those obtained in AlGaN: Eu and AlGaN: Er [30] and this is normal in the case of co-doping with Eu and Er atoms. Additionally, the total magnetic moment seems to originate from N, Ga, and Al atoms in relation to Eu and Er.…”

“…Å for c. The bulk modulus is reduced to 188.51 GPa, and the B coe cient is 4.51. Similarly, for Er doping in Al 0.25 Ga 0.75 N (Al 0.25 Ga 0.75 N: Er)[30], the lattice constants remain similar, with values of 3.19 Å for a and 5.17 Å for c.The bulk modulus is reported as 192.91 GPa, and the B coe cient is 4.45. In the case of co-doping with Eu and Er in Al 0.25 Ga 0.75 N (Al 0.25 Ga 0.75 N: Eu/Er), the lattice constants increase further to 3.25 Å for a and 5.28 Å for c. The bulk modulus decreases to 181.429 GPa, and the B' coe cient is 3.96.…”

“…The valence electrons Ga 3d 10 4s 2 4p 1 , Al 3s 2 3p 1, and N 2s 2 2p 3 are taken into consideration. We chose the isoelectronic trivalent con guration of the rare-earth elements 4f 6 5d 1 6s 2 for Eu and 4f 11 5d 1 6s 2 for Er since it is the valency that has been shown to be favoured in prior calculations [30,31] and experiments [54,55]. The signi cant correlation impact of the Eu and Er 4f electrons is taken into account using the local spin density approximation with Hubbard-U corrections (LSDA + U), with U values of 0.54 Ry and 0.62 Ry, respectively, determined from Ref.…”

“…The lattice constants rise somewhat, as indicated in Table 1 of 0.099 Å for a and 0.187 Å for c after structural optimisation. When Eu is doped into Al 0.25 Ga 0.75 N (Al 0.25 Ga 0.75 N: Eu) [30], the lattice constants slightly increase to 3.20 Å for a and 5.17 The PDOS of AlGaN: Eu/Er (Fig. 2) are given for Eu-5d, Er-5d, Eu-4f, Er-4f, Al-2p, Ga-3p, and N-2p.…”

“…Using OMVPE-grown GaN: Eu as an active layer, electroluminescence from a GaN-based LED has been successfully shown [27]. In our previous study, we demonstrated that AlGaN: RE (RE = Tm, Gd, Eu, Er) [28][29][30] and InGaN: RE (RE = Er, Eu, Tm) [31,32] exhibit a semiconductor character with a magnetic moment of 6.00, 3.00, 1.98, 7.15, and 3.02 for AlGaN: Eu, AlGaN: Er, AlGaN: Tm, AlGaN: Gd, and InGaN: Er, respectively. Akazawa et al [33] investigate the behaviour of Eu 3+ and Er 3+ ions when they are simultaneously introduced into ZnO thin lms.…”