Spintronics: A Challenge for Materials Science and Solid‐State Chemistry

Abstract

Spintronics is a multidisciplinary field involving physics, chemistry, and engineering, and is a new research area for solid-state scientists. A variety of new materials must be found to satisfy different demands. The search for ferromagnetic semiconductors and stable half-metallic ferromagnets with Curie temperatures higher than room temperature remains a priority for solid-state chemistry. A general understanding of structure-property relationships is a necessary prerequisite for the design of new materials. In this Review, the most important developments in the field of spintronics are described from the point of view of materials science.

Fabrication of FeSi and Fe3Si compounds by electron beam induced mixing of [Fe/Si]2 and [Fe3/Si]2 multilayers grown by focused electron beam induced deposition

“…If, on the other hand, a suitable precursor is not available, the fabrication of binary alloys can take place by the use of two homonuclear precursor gases, each containing one 8 of the two required atomic species. In the last years, several precursors, like F e(CO) 5 , Co 2 (CO) 8 , Si 5 H 12 and (CH 3 ) 3 CH 3 C 5 H 4 P t have been employed to fabricate F eP t, P tSi CoP t and CoSi alloys [14][15][16][17]. In these studies, in order to obtain the stoichiometry of interest, the precursors were mixed continuously by changing their relative flux.…”

“…F e 3 Si and F e 5 Si 3 are room-temperature ferromagnets attractive for spintronics [5,6]. In particular, F e 3 Si is a pseudo-Heusler alloy with D0 3 structure, equivalent to the L2 1 structure of full-Heusler compounds, which are predicted to be half-metallic [7,8]. Conventionally, the preparation of Fe-Si binary alloys takes place by means of solid-state reactions [9,10].…”

The role of chemical structure on the magnetic and electronic properties of Co2FeAl0.5Si0.5/Si(111) interface

“…Co-based Heusler alloys have been attracting a lot of attention due to their predicted 100% spin polarization at the Fermi level, making them an ideal material of choice for many spintronic applications. [1][2][3][4][5] Among the half-metallic ferromagnetic (HMF) full Heusler alloys of the form X 2 YM (X,Y: transition metals, M: main group elements), Co 2 FeAl 0.5 Si 0.5 (CFAS) is of particular interest due to its high Curie temperature T C and giant tunnel magnetoresistance ratio at room temperature when used as an electrode in magnetic tunnel junctions. 6 The integration of HMF materials in existing largescale integrated circuits technologies could enable the development of fast and ultra-low power consumption Si-based spintronic devices.…”

“…It is worth noting that along the [1][2][3][4][5][6][7][8][9][10] orientation of the fully ordered L2 1 phase, where Co, Fe, and Al/Si occupy the X, Y, and M sites, respectively, each atomic column is occupied by single species of Co, Fe, while Al/Si share the same atomic columns. In contrast to L2 1 , for films with B2 ordering, only the Co sub-lattice (populating the X sites) is fully ordered, whilst the Fe and Al/Si atomic species are intermixed (Y-M atomic sites mixing).…”

Molecular Chemistry to the Fore: New Insights into the Fascinating World of Photoactive Colloidal Semiconductor Nanocrystals

“…29 These highly versatile photoactive nanomaterials are well-known to benefit from size-and composition-tunable band gaps (300−4000 nm; 4.1−0.3 eV), 1,30−32 broad and intense absorption (ε ≈ 10 6 L·mol −1 ·cm −1 ), 33,34 long-lived excited states (up to 40 ns for CdSe, 500 ns for CuInS 2 , 1.8 μs for PbS), 35−37 colloidal stability, and chemical and photostability. 20,38−42 The optical properties of semiconductor nanocrystals are unmatched by other synthetic chromophores and fluorophores such as organic dyes or transition-metal complexes.…”