Extended Data Fig. 1: Description of the spark ablation and electrostatic deposition experimental set-up, operation, and electrical components.

(a) Faraday cup used to collect either negatively or positively charged particles from the aerosol. The measured current (via an electrometer) allows to determine the number of ions hitting the cup per unit of time giving a measure of the ablation rate (cluster production rate)^77,78. (b) Deposition chamber allowing for a filter deposition in which the entire aerosol flow is passed through a substrate as well as an electrostatic deposition method in which a bias is applied to a substrate and as such only particles of opposite polarity are adhered to it⁷⁹. (c) Aerosol exhaust. (d) Positive electrode (grounded). (e) Spark chamber. (f) Carrier gas (Ar) flow inlet. Direction of flow is from (E) to (B). (g) Negative electrode. (h) Pin-to-hole configuration of the electrode set-up of the spark ablator showing two Cu electrodes⁸⁰. Exchanging the pin or negative electrode for Ag allows for the production of bimetallic clusters^81,82,83,84. (i) Picture of the spark in operation. (j) Resistance-inductance-capacitance (RLC) electrical circuit, in which I denote the power supply. C denote(s) the capacitor, L denotes the inductor needed to store potential energy via the magnetic field needed for the oscillatory nature of the spark⁸⁵. The spark is indicated by the damped exponential with a ~100 ns time constant of the oscillation of the spark between the grounded and negative electrode.