Effect of single and mixed Bi, Ga doping on the magnetic properties of Y3Fe5O12

The stability, structural, magnetic, and band structure properties of Y3Fe5O12, Y2.75Bi0.25Fe5O12, Y3Fe4GaO12, and Y2.75Bi0.25Fe4GaO12 solid solutions were studied by first-principles calculations. The results demonstrated that the substitution of Bi3+ induces a reduction in the bandgap of Y3Fe5O12. At the same time, Ga3+ was introduced in both the octahedral and tetrahedral sites of Fe3+ and it was found that the bandgap remained almost unchanged. On the other hand, the magnetization was reduced with the incorporation of Bi3+, coinciding with the experimental trend observed in the literature while increasing with Ga3+ incorporation. This behavior is attributed to the disruption of the magnetic sublattices. These results help to understand the ferrimagnetic behavior of YIG and encourage its use as a promising material for optoelectronic and spintronic applications. It is also shown that there is a margin for manipulating the magnetic response through appropriate doping.