Superconducting resonators with high quality factors have been fabricated from aluminum films, suggesting potential applications in quantum computing. Improvement of thin film crystal quality and removal of void and pinhole defects will improve quality factor and functional yield. Epitaxial aluminum films with superb crystallinity, high surface smoothness, and interface sharpness were successfully grown on the c-plane of sapphire using sputter beam epitaxy. This study assesses the effects of varying substrate preparation conditions and growth and prebake temperatures on crystallinity and smoothness. X-ray diffraction and reflectivity measurements yield extensive Laue oscillations and Kiessig thickness fringes for films grown at 200 °C under 15 mTorr Ar, indicating excellent crystallinity and surface smoothness; moreover, an additional substrate preparation procedure which involves (1) a modified substrate cleaning procedure and (2) prebake at 700 °C in 20 mTorr O₂ is shown by atomic force microscopy to yield nearly pinhole-free film growth while maintaining epitaxy and high crystal quality. The modified cleaning procedure is environmentally friendly and eliminates the acid etch steps common to conventional sapphire preparation, suggesting potential industrial application both on standard epitaxial and patterned surface sapphire substrates.

This paper contains data and results from Density Functional Theory (DFT) investigation of 423 distinct X₂YZ ternary full Heusler alloys, where X and Y represent elements from the D-block of the periodic table and Z signifies element from main group. The study encompasses both "regular" and "inverse" Heusler phases of these alloys for a total of 846 potential materials. For each specific alloy and each phase, a range of information is provided including total energy, formation energy, lattice constant, total and site-specific magnetic moments, spin polarization as well as total and projected density of electronic states. The aim of creating this dataset is to provide fundamental theoretical insights into ternary X₂YZ Heusler alloys for further theoretical and experimental analysis.

We report a resonant elastic x-ray scattering study of a thin-film sample of ${\mathrm{Sr}}_2{\mathrm{CrReO}}_6$, which has one of the highest ferrimagnetic transition temperatures among ordered double perovskites. We found resonantly enhanced magnetic Bragg peaks at $\mathbf{Q}=$ (odd, odd, odd) at both the rhenium $L_2$ and $L_3$ edges, which coincide with the structural Bragg peaks of ${\mathrm{Sr}}_2{\mathrm{CrReO}}_6$. By analyzing the widths of these Bragg peaks, we extracted very different structural and magnetic correlation lengths. The former is about 15 nm, while the latter is constrained by the instrumental resolution to be at least 90 nm. We argue that a finite structural correlation length is consistent with the existence of antiphase nanodomains in our sample. On the other hand, a much larger magnetic correlation length indicates that the magnetic correlation extends far beyond the boundaries of individual domains and is consistent with strong antiferromagnetic coupling between different antiphase domains. Last, from the azimuthal dependence of the magnetic intensity, we show that the magnetic moments lie perpendicular to the $c$ axis, which explains the earlier bulk magnetization data.

We describe a magnetic force microscopy (MFM) imaging approach in which we take advantage of the strong, localized magnetic field of the MFM probe to deterministically modify the magnetization of the sample. This technique enables quantitative mapping of sample magnetic properties including saturation magnetization and anisotropy, a capability not generally available using conventional MFM methods. This approach yields a fruitful theoretical analysis that accurately describes representative experimental data we obtain from an isolated permalloy disk.