Supercurrent suppression by the injection of spin-polarized quasiparticle current from a ferromagnet into a superconductor is demonstrated in YBa2Cu3O7−δ/SrTiO3/La0.7Sr0.3MnO3−δ junctions at 77 K. Negative current gains as large as 35 have been observed. The magnitude of the effect depends on the net polarization of the injection current, film resistivities, barrier microstructure, and injection geometry. Fabrication of the junctions is discussed in terms of optimizing these parameters for maximum supercurrent suppression.
We have characterized two chemical etchants for A1GaInP: hot sulfuric acid (H2SO4, at 60 and 70~ and dilute hydrochloric acid (1HClrlH20, at room temperature). Both chemicals are selective with composition, etching Ga0.sIno.sP slowly, and A10.sIn05P at the rate of several hundred A/s. When used to etch'laser structures, these etchants are anisotropic, resulting in approximate {111} sidewalls. For (A10.TGa0.3)0.sIn0.sP, a common alloy for laser cladding layers, the etching is also dependent upon carrier concentration. For example, while the H2SO4 at 60~ and the 1HCl:lH20 etch n-and un-doped material at a rapid rate, they are very much slower for the p-doped alloy. In contrast, hotter H2SO4 (T -> 70~ is not so selective with doping.
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.