A room-temperature magnetic semiconductor from a Co-Fe-Nb-B metallic glass

New Class of Amorphous Oxide Semiconductors from Amorphous Alloys

“…Consequently, metals with stronger oxygen affinities prefer to bond with oxygen atoms. Such selective oxidization leads to a locally inhomogeneous distribution of oxygen, enabling the formation of both oxygen-rich and oxygen-deficient chemical short-range orders (CSROs) with different local atomic configurations in these AOSs. − Among the constituents, Al and Zr have the highest formation enthalpies of the corresponding crystalline oxides, as shown in Figure . Therefore, they attract oxygen atoms the most.…”

“…Amorphous alloys (AAs) possess superior chemical, physical, and mechanical properties owing to unique disordered atomic structures characterized primarily by metallic bonding. − Through oxygen-mediated metal–semiconductor transitions, ferromagnetic AOSs including both p-type and n-type conduction have been developed from Co–Fe-based ferromagnetic amorphous alloys (FAAs). − Their conduction types are closely related to the local atomic short-range orders and metal valence states in the systems . Basically, the ability to transform these FAAs into magnetic AOSs is attributed to their intrinsic amorphous structures dominated by nondirectional and nonsaturating metallic bonding, no matter whether they are ferromagnetic or nonferromagnetic.…”

Fabrication and structural and magnetic properties of spark plasma sintered group-IV diluted magnetic semiconductor Fe-doped SiGe alloys

“…Diluted magnetic semiconductors (DMSs) have received much interest due to their potential applications in spintronic semiconductor devices with advantages of low energy consumption, high speed, and non-volatility compared to traditional semiconductor devices [1][2][3][4]. Among those previously-reported DMSs [5][6][7][8][9][10][11], group-IV DMSs are particularly promising for the development of semiconductor spintronics, because both the spin and charge degrees of freedom can be utilized in group-IV semiconductors compatible with the mainstream semiconductor integration technology [12,13]. However, group-IV DMSs suffer from the facts that not only most of their Curie temperature (T C ) values are lower than room temperature [12][13][14][15][16], but also their ferromagnetic orderings often have the contributions from magnetic dopant-related inhomogeneity, clusters, and/or second-phase precipitates [17][18][19][20].…”

Magnetic Semiconductors from Ferromagnetic Amorphous Alloys

“…Recent reports show that FAAs can be used as precursors for producing new kinds of amorphous magnetic semiconductors (AMSs) via oxygen mediated metal-semiconductor transition [8][9][10]. Generally, magnetic semiconductors are prepared by adding magnetic elements into non-magnetic semiconductors, forming diluted magnetic semiconductors (DMSs) [11][12][13][14][15][16][17].…”

“…However, these DMSs usually show Curie temperatures lower than room temperature, which becomes the key barrier to hampering their practical application [18]. In contrast, the AMSs show high curie temperatures above room temperature because they are transferred from the properly selected FAAs with Curie temperatures much higher than room temperature [8][9][10]. These AMSs enable the realization of electric field control of ferromagnetism [8,9], showing potential for application in spintronic devices.…”