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Preventing stray magnetic interactions is important to improving technology that relies upon manipulating an electron's charge and spin. To this end, the authors investigate a binary intermetallic that has an internal magnetic field, yet does not affect the spin of surrounding components. As-grown epitaxial thin films of Mn${}_{3}$Al on GaAs(001) present the the ideal D0${}_{3}$ Heusler phase. This compound should be quite interesting for optimizing tomorrow's spintronic devices.

The electronic and structural properties of thin LaNiO₃ films grown by using molecular beam epitaxy are studied as a function of the net ionic charge of the surface terminating layer. We demonstrate that electronic transport in nickelate heterostructures can be manipulated through changes in the surface termination due to a strong coupling of the surface electrostatic properties to the structural properties of the Ni—O bonds that govern electronic conduction. We observe experimentally and from first-principles theory an asymmetric response of the structural properties of the films to the sign of the surface charge, which results from a strong interplay between electrostatic and mechanical boundary conditions governing the system. The structural response results in ionic buckling in the near-surface NiO₂ planes for films terminated with negatively charged NiO₂ and bulklike NiO₂ planes for films terminated with positively charged LaO planes. The ability to modify transport properties by the deposition of a single atomic layer can be used as a guiding principle for nanoscale device fabrication.