arXiv subjects

D. S. Yakovlev

Publications and source records attributed to D. S. Yakovlev.

2 recordsLinked to original sources

arXiv2026

Production of a Titanium Ion Beam Using Fluorides and Fluorine-Forming Precursors in an ECR Ion Source

The production of multiply charged titanium ions is of significant interest for accelerator-based experiments, surface modification technologies, and applications in nuclear physics. Due to the low saturated vapor pressure of titanium at temperatures below 1000 °C, the generation of titanium ion beams from an electron cyclotron resonance ion source (ECRIS) remains a challenging task. The choice of titanium vapor injection methods into the ECR plasma plays a key role in achieving high ionization efficiency, plasma stability, and reliable long-term source operation. In this work, alternative approaches for the injection of neutral titanium atoms into the ECR plasma are investigated, focusing on the use of fluorine-containing compounds. Titanium fluorides (TiF3, TiF4) possess a relatively high saturated vapor pressure at moderate temperatures, allowing to use standard resistively heated ovens operating up to 1000 °C. Another method involves the in-situ formation of titanium fluorides inside the plasma chamber via chemical reactions between metal titanium and the dissociation products of sulfur hexafluoride (SF6). These approaches enable controlled and efficient titanium injection into the ECRIS plasma with satisfactory extracted ion beam stability.

physics.acc-ph↗

arXiv2024

Nanopatterning of multicomponent van der Waals heterostructures using atomic force microscopy

Multilayer van der Waals (vdW) heterostructures have become an important platform in which to study novel fundamental effects emerging at the nanoscale. Standard nanopatterning techniques relying on electron-beam lithography and reactive ion etching, widely applied to pattern such heterostructures, however, impose some limitations on the edge accuracy and resolution, as revealed through numerous experiments with vdW quantum dots and point contacts. Here we present an alternative approach for electrode-free nanopatterning of thick multilayer vdW heterostructures based on atomic force microscopy (AFM). By applying an AC voltage of a relatively small frequency (1-10 kHz) between the sharp platinum tip and the substrate, we realize high-resolution ($\lesssim 100$ nm) etching of thick multicomponent heterostructures if the latter are deposited onto graphite slabs. Importantly, unlike more conventional electrode-free local anodic oxidation, our method does not require a special environment with excess humidity, can be applied at ambient conditions, and enables the patterning of multilayer heterostructures composed of graphene, graphite, hexagonal boron nitride (hBN), NbSe$_{2}$, WSe$_{2}$, and more.

cond-mat.mes-hall↗