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The electrical resistivity of conventional metals such as copper is known to increase in thin films as a result of electron-surface scattering, thus limiting the performance of metals in nanoscale electronics. Here, we find an unusual reduction of resistivity with decreasing film thickness in niobium phosphide (NbP) semimetal deposited at relatively low temperatures of 400°C. In films thinner than 5 nanometers, the room temperature resistivity (~34 microhm centimeters for 1.5-nanometer-thick NbP) is up to six times lower than the resistivity of our bulk NbP films, and lower than conventional metals at similar thickness (typically about 100 microhm centimeters). The NbP films are not crystalline but display local nanocrystalline, short-range order within an amorphous matrix. Our analysis suggests that the lower effective resistivity is caused by conduction through surface channels, together with high surface carrier density and sufficiently good mobility as the film thickness is reduced. These results and the fundamental insights obtained here could enable ultrathin, low-resistivity wires for nanoelectronics beyond the limitations of conventional metals. 

A universal synthesis strategy of coating crystalline core colloidal nanoparticles with amorphous metallic glass shell. We can form conformal CoB and NiB shell coatings with controlled thicknesses on different sized Au and Pt core nanoparticles. 

We have stabilized epitaxial oxide thin films of transparent, magnetic Ru-doped BaSnO3. Films were grown by pulsed laser deposition and exhibited excellent epitaxy and crystallinity as determined by x-ray diffraction. Epitaxial films of Ru doped BaSnO3 were grown with a ceramic target of nominally 4% Ru doping on the Sn site but resulted in 3% Ru doping in the  lms. Paramagnetic behavior is observed in all  lms with a Curie law dependence on temperature. The field dependence of the magnetization shows a paramagnetic moment that saturates at a value consistent with low spin Ru. Films are also found to be transparent in the visible regime. Together these results demonstrate the realization of highly crystalline, transparent, paramagnetic,epitaxial doped BaSnO3 films. 

Complex ferromagnetic oxides have been identified as possible candidate materials for sources of spin currents. Here we study bilayers of ferromagnetic (La2/3Sr1/3)MnO3 (LSMO) and metallic CaRuO3 (CRO) on LSAT substrates as a model system for spin pumping. Ferromagnetic resonance (FMR) measurements of these bilayers show evidence of spin pumping across the interface in the form of an increase in Gilbert damping with the addition of CRO. FMR indicates that the presence of CRO modifies the magnetic anisotropy of the LSMO. By increasing CRO thickness, we find a reduction of the out-of-plane anisotropy and simultaneous rotation of the easy axis within the plane, from the ⟨110⟩ to ⟨100⟩ axis. The evolution of magnetic anisotropy determined by FMR disagrees with that measured by bulk SQUID magnetometry and is accompanied by structural distortions in the LSMO layer as measured by x-ray diffraction, thus suggesting a change in magnetic anisotropy attributed to structural distortions imposed on LSMO by CRO. These results suggest that while LSMO and CRO remain promising candidates for efficient pure spin current generation and detection, respectively, epitaxial integration of perovskites will cause additional changes which must be accounted for in spintronics applications.