Thin films of the semiconducting compound Mg 2 Ge were deposited by magnetron cosputtering from source targets of high-purity Mg and Ge onto glass substrates at temperatures T s = 300°C to 700°C. X-ray diffraction shows that the Mg 2 Ge compound begins to form at a substrate temperature T s % 300°C. Films deposited at T s = 400°C to 600°C are single-phase Mg 2 Ge and have strong x-ray peaks. At higher T s the films tend to be dominated by a Ge-rich phase primarily due to the loss of magnesium vapor from the condensing film. At optimum deposition temperatures, 550°C to 600°C, films have an electrical conductivity r 600 K = 20 X À1 cm À1 to 40 X À1 cm À1 and a Seebeck coefficient a = 300 lV K À1 to 450 lV K À1 over a broad temperature range of 200 K to 600 K.
Magnetic properties and high frequency characteristics of binary Co100−xTax (x = 0–24) thin films, prepared by using the oblique sputtering method under an external magnetic field of 1200 Oe have been studied. All the Co100−xTax films are easy to form amorphous phase, and thus exhibit strong in-plane uniaxial magnetic anisotropy, high resistivity, and low coercivity. With increasing x, the saturation magnetization (4πMs) and coercivity along the easy and hard axes (Hce and Hch) are decreased, while the magnetic anisotropy field (Hk) reaches the maximum value of 578 Oe for the films with the composition to become fully amorphous phase. Due to large Hk, high ferromagnetic-resonance frequency (fFMR) of 4.7–6.6 GHz is obtained for Co100−xTax (x = 11–24) films. The optimal magnetic properties of 4πMs = 10.9 kG, Hce = 6.2 Oe, Hch = 6.0 Oe, Hk = 507 Oe, and high resonance characteristics of fFMR = 6.4 GHz, respectively, are reached for Co84Ta16 films. Finally, high fFMR of 5.4–7.2 GHz and Hk of 434–617 Oe can be tuned by the modification of the sputtering parameters. This result reflects the benefit of Co100−xTax (x = 11–22) films for above 5 GHz applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.