MgB2 thin films by hybrid physical–chemical vapor deposition

Low noise terahertz MgB2 hot-electron bolometer mixers with an 11 GHz bandwidth

“…Although such a high J c indicates thin MgB 2 films of high quality, some scattering of the critical currents and normal state resistances probably points to some variations of film defects/thickness across the substrate. Published morphology studies of 5-10 nm thick MgB 2 films, also made with HPCVD, showed 17 that MgB 2 films were not fully connected, and that there were gaps of tens of nanometers between islands of MgB 2 for films thinner than 15 nm. We have not yet been able to conduct morphology studies on our films; however, it appears that in our case, MgB 2 films merge into a continuous structure at smaller thicknesses than previously reported.…”

MgB2 ultrathin films fabricated by hybrid physical chemical vapor deposition and ion milling

“…MgB 2 films grown by methods such as the co-evaporation process 13 and molecular beam epitaxy [14][15][16][17][18] suffer from a significant drop in critical temperature (T c ) when the film thickness decreases. Compared to those, ultrathin films grown by hybrid physical-chemical vapor deposition (HPCVD) exhibit superior quality 19,20 and display a T c of up to 36 K for 10 nm thick films. 21 Although the HPCVD process results in highly epitaxial MgB 2 films, the films display weak grain connectivity in the ultrathin regime due to the characteristic island growth of MgB 2 .…”

Influence of Mg Vapor Pressure on the <TEX>$MgB_2$</TEX>/Carbon Fiber Fabricated by Physical Vapor Deposition method

“…2c), where only (100) and (101) peaks are shown at 2 33.52 and 42.46, respectively. When the Mg vapor pressure was further decreased, the peak intensities of MgB 2 simply decreased without forming other phases including MgB 4 or MgB 7 as in Fig. 2d).…”

“…Although many efforts have been devoted to fabricate MgB 2 bulk, wire, or film for the application in various areas, there still remain lots of obstacles to overcome, especially in long-length thin film MgB 2 wire synthesis. Generally, MgB 2 films have been synthesized by hybrid physical-chemical vapor deposition (HPCVD) [4], molecular beam epitaxy (MBE) [5], reactive evaporation [6], ultra high vacuum method (UHV) [7], electron beam evaporation (EBE) [8], and pulsed laser deposition (PLD) [9]. These methods normally adopt ex-situ or in-situ annealing process during MgB 2 formation reaction.…”