Conductive nanodots on the surface of irradiated CaF2

TL;DR

This study demonstrates that swift heavy ion irradiation creates metallic calcium nanodots on CaF2 surfaces, which exhibit enhanced conductivity detectable via magnetic AFM, revealing potential for nanoscale electronic applications.

Contribution

It introduces a non-contact magnetic AFM method to characterize conductivity of nanodots formed by ion irradiation on CaF2 surfaces, showing their metallic nature.

Findings

Nanodots exhibit enhanced electromagnetic interaction with magnetic AFM tips.

Energy dissipation per cycle suggests metallic calcium nanodots.

Method confirms metallic properties of ion-induced nanostructures.

Abstract

CaF2(111) single crystal surfaces have been irradiated with swift heavy ions under oblique angles resulting in chains of nanosized hillocks. In order to characterize these nanodots with respect to their conductivity we have applied non-contact atomic force microscopy using a magnetic tip. Measurements in UHV as well as under ambient conditions reveal a clearly enhanced electromagnetic interaction between the magnetic tip and the nanodots. The dissipated energy per cycle is comparable to the value found for metals, indicating that the interaction of the ion with the target material leads to the creation of metallic Ca nanodots on the surface.