Searching for stable 2D gallium and indium oxides
Searching for stable 2D gallium and indium oxides lead image
Researchers are searching for 2D materials with properties relevant to various applications. These materials must exhibit high structural and thermal stabilities and not be too difficult to synthesize.
Meng et al. explored all possible 2D phases of gallium oxides and indium oxides with the Universal Structure Predictor: Evolutionary Xtallography (USPEX) method, an evolutionary algorithm. The authors found Ga2O3 and In2O3 to be the most stable atomic configurations. They confirmed the structural and thermal stability of these configurations by calculating their formation energies, phonon dispersion curves and molecular dynamics simulations.
Additionally, this study determined Ga2O3 and In2O3 monolayers are nonmagnetic semiconductors, but hole doping can change them into ferromagnetic materials as well as transform them into half-metals over a wide range of hole densities. This introduced ferromagnetism makes these 2D materials promising for spintronic devices. The bilayer structure of Ga2O3 is ferromagnetic without hole doping.
“To our best of knowledge, this is the first try to search for the globally stable 2D form of the gallium oxides and indium oxides,” said author Ruishen Meng. “It could inspire the experimental synthesis of these new 2D materials and also motivate the study of the ferromagnetism of the 2D materials upon hole doping.”
Using Monte Carlo simulations, the authors also found the estimated Curie temperatures of the Ga2O3 and In2O3 monolayers and the Ga2O3 bilayer are comparable to 2D transition metal halides. They plan to explore alternative methods for hole doping 2D gallium oxides and indium oxides, such as adatom doping and defects.
Source: “Two-dimensional gallium and indium oxides from global structure searching: Ferromagnetism and half metallicity via hole doping,” by Ruishen Meng, Michel Houssa, Konstantina Iordanidou, Geoffrey Pourtois, Valeri Afanasiev, and André Stesmans, Journal of Applied Physics (2020). The article can be accessed at https://doi.org/10.1063/5.0012103 .
