The fabrication and characterization of half-Heusler YPdBi thin films

The electrical, optical, and magnetic properties of half-Heusler compounds make them novel interesting materials being studied by many groups worldwide. The synthesis of YPdBi, a member of half-Heusler compounds, thin films have been achieved at different deposition temperatures such as 360 degrees C and 470 degrees C by employing magnetron co-sputtering technique. X-ray diffraction (XRD) examinations have revealed that the film deposited at 360 degrees C has a slightly larger lattice parameter, 6.82 angstrom, than the film fabricated at 470 degrees C, having 6.73 angstrom. The induced strain of the films has been 2.1% and 0.7% for the films deposited at 360 degrees C and 470 degrees C, respectively. Xray photoelectron spectroscopy (XPS) investigations have revealed the obtained films have the stoichiometry close to the 1:1:1 ratio. Scanning electron microscopy (SEM) studies have shown that surface topography varies dramatically as the deposition temperature advances. Furthermore, high-resolution scanning transmission electron microscopy (STEM) has shown that layer-plus-island growth known as the Stranski-Krastanov (SK) growth mode, taking place due to minimization of strain energy, leads to the island formation from a specific film thickness on. It has been shown that while the resistance of the sample grown at 470 degrees C changes abruptly at 2.45 K, which indicates the onset of superconductivity, the sample deposited at 360 degrees C does not show this effect. The absence of the onset of superconductivity in this latter case might be associated with the lattice strain and intensive scattering in this sample.

Automated summary

The study successfully synthesized thin films of half-Heusler compound YPdBi and characterized them using techniques like XRD, XPS, SEM, and STEM, showing that different deposition temperatures affect the film's lattice, strain, and stoichiometry, with a noticeable impact on superconducting properties.