Two new precursors for focused electron beam-induced deposition (FEBID) of cobalt silicides have been synthesized and evaluated. The H3SiCo­(CO)4 and H2Si­(Co­(CO)4)2 single-source precursors retain the initial metal ratios and show low sensitivity to changes in the FEBID parameters such as acceleration voltage, beam current, and precursor pressure. The precursors allow the direct writing of material containing ∼55 to 60 at % total metal/metalloid content combined with high growth rates. During the deposition process an average of ∼80% of the carbonyl ligands are cleaved off in these planar deposits. Postgrowth electron curing does not change the deposits’ composition, but resistivities decrease after the curing procedure. Temperature-dependent electrical properties indicate the presence of a granular metal for both cured samples and the as-grown Co2Si deposit, while the as-grown CoSi material is on the insulating side of the metal–insulator transition. The observed magnetoresistance behavior is indicative of tunneling magnetoresistance and is substantially reduced upon postgrowth irradiation treatment.

Bulk EuPd 2 Si 2 show a temperature-driven valence transition of europium from ∼ + 2 above 200 K to ∼ + 3 below 100 K, which is correlated with a shrinking by approximately 2% of the tetragonal crystal lattice along the two a-axes. Due to this interconnection between lattice and electronic degrees of freedom the influence of strain in epitaxial thin films is particularly interesting. Ambient x-ray diffraction (XRD) confirms an epitaxial relationship of tetragonal EuPd 2 Si 2 on MgO(001) with an out-of plane c-axis orientation for the thin film, whereby the a-axes of both lattices align. XRD at low temperatures reveals a strong coupling of the thin film lattice to the substrate, showing no abrupt compression over the temperature range from 300 to 10 K. Hard x-ray photoelectron spectroscopy at 300 and 20 K reveals a temperature-independent valence of +2.0 for Eu. The evolving biaxial tensile strain upon cooling is suggested to suppress the valence transition. Instead temperature-dependent transport measurements of the resistivity and the Hall effect in a magnetic field up to 5 T point to a film thickness independent phase transition at 16 to 20 K, indicating magnetic ordering.

The material composition and electrical properties of nanostructures obtained from focused electron beam-induced deposition (FEBID) using manganese and vanadium carbonyl precursors have been investigated. The composition of the FEBID deposits has been compared with thin films derived by the thermal decomposition of the same precursors in chemical vapor deposition (CVD). FEBID of V(CO)6 gives access to a material with a V/C ratio of 0.63–0.86, while in CVD a lower carbon content with V/C ratios of 1.1–1.3 is obtained. Microstructural characterization reveals for V-based materials derived from both deposition techniques crystallites of a cubic phase that can be associated with VC1−xOx. In addition, the electrical transport measurements of direct-write VC1−xOx show moderate resistivity values of 0.8–1.2 × 103 µΩ·cm, a negligible influence of contact resistances and signatures of a granular metal in the temperature-dependent conductivity. Mn-based deposits obtained from Mn2(CO)10 contain ~40 at% Mn for FEBID and a slightly higher metal percentage for CVD. Exclusively insulating material has been observed in FEBID deposits as deduced from electrical conductivity measurements. In addition, strong tendencies for postgrowth oxidation have to be considered.