Ions Passage Through Nanodroplets in a Multicomponent Beam

I. Hasanov, I. Gurbanov, E. Akbarov Institute of Physics of ANAS, G. Javid av., 131, Az1143 Baku, Azerbaijan

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The report is a part of researches of the characteristics of nanodisperse phase of liquid metal ion source. In the certain mode of the liquid metal source the ions and the nanodroplets are simultaneously generated. Fast ions (In, Sn, Au, Ge) are passing through droplets and are losing a part of energy at collisions. Generation of nanodroplets is accompanied by excitation of capillary waves on the surface of the liquid emitter which results in high-frequency modulation of the ion current. In the experiments, droplets with the sizes of 2-20 nm and a characteristic specific charge of 5×104 C/kg were registered. Energy spectra of ions were defined by means of the filter of speeds (Vine's filter) with crossed static electromagnetic fields. The reduction of energy of In+ ions in near-axis areas of the beam achieves 250 eV at acceleration voltage of 6 kV in the conditions of our measurements. Outside of this area there are no losses of energy, as the nanodroplets extend along the beam axis. Penetration depth of the accelerated ions in liquid indium is estimated within the framework of the model of Linhard-Scharff-Schiott, considering interaction of ions with nuclei of the target. A similar interaction between components has to be considered in ion-beam systems with complex composition where there is a relative movement of the various charged particles. Nanodroplet deposition on a conductive surface is of interest for creation of various nanostructures. By having a substrate at a distances of tens microns from the needle and by moving it with respect to the needle by means of piezostage, indium stripes of micron width were deposited.

DOI:10.12693/APhysPolA.134.119 topics: ion source, ion beam, energy spectra, nanoparticle