Electrical and structural properties of MgB2 films prepared by sequential deposition of B and Mg on the NbN-buffered Si(100) substrate

Abstract

We introduce a simple method of an MgB 2 film preparation using sequential electron-beam evaporation of B-Mg two-layer (followed by in-situ annealing) on the NbN buffered Si (100)

Superconducting MgB2 Microstrips

“…1, dashed line) under the same fabrication procedure. The X-ray and transmission electron microscope analyses showed polycrystalline character of the films grown on NbN/Si substrate and no Mg 2 Si or MgO were detected [3]. On the one hand NbN allows to increase T C0 of MgB 2 , but on the other hand it brings additional superconducting transition at lower temperatures (below 10-12 K), as it is seen in Fig.…”

“…The B-Mg bilayer was annealed in-situ for 10 min at 720 • C in Ar atmosphere of 16 Pa pressure. Further details of the in-situ MgB 2 thin film processing are described elsewhere [3,5]. A photoresis mask and Ar ion beam etching with ion energy of 400 eV for patterning of the microstrips were used.…”

“…The MgB 2 thin films were prepared by a sequential evaporation of boron and magnesium and synthesized by in-situ annealing [3]. The B and Mg layers were deposited on NbN (thickness ≈ 100 nm) buffered Si(100) single crystal substrate.…”

“…MgB 2 superconducting films prepared in-situ on SiC substrate exhibit excellent epitaxial growth and critical current density j C ≈ 3.5 × 10 7 A/cm 2 at 4.2 K [2]. Recently we have presented an alternative NbN buffered Si(100) substrate suitable for the preparation of MgB 2 superconducting thin films [3] and Josephson junctions [4]. The maximal zero resistance critical temperature T C0 = 36 K was achieved, close to the bulk value (∼ 40 K), and critical current density was estimated to j C ≈ 3 × 10 7 A/cm 2 at 13.2 K [3].…”

“…Recently we have presented an alternative NbN buffered Si(100) substrate suitable for the preparation of MgB 2 superconducting thin films [3] and Josephson junctions [4]. The maximal zero resistance critical temperature T C0 = 36 K was achieved, close to the bulk value (∼ 40 K), and critical current density was estimated to j C ≈ 3 × 10 7 A/cm 2 at 13.2 K [3]. In this paper we present some electrical transport properties of MgB 2 thin films and microstrips patterned by Ar ion-beam etching.…”