Structural and magnetic properties of nickel catalyzed-tungsten oxide nanosheets synthesized using e-beam rapid thermal annealing

Ni-catalysed WO3 nanostructures grown by electron beam rapid thermal annealing for NO2 gas sensing

“…Silicon substrate peak was observed at 2h = 55.744°. The presence of (200) plane peak corresponding to metallic nickel indicated that nickel initially seems to grow pseudomorphically on the Si substrate, but soon changes the growth pattern to the more favourable (111) phase (Gopalakrishnan et al 2012). The formation of Ni (111) phase can be attributed to the high lattice mismatch between silicon and nickel (*35 %).…”

“…This could be because of the low diffraction angle and relatively thicker WO 3 layer or the diffusion of Ni into the crystal structure of WO 3 . It is presumed that a part of the nickel from the underlying layer is transported into the overlying WO 3 layer upon ERTA (Gopalakrishnan et al 2011(Gopalakrishnan et al , 2012. This indicates the inclusion of metallic nickel in the WO 3 matrix.…”

“…Samples 'A' and 'B' were subjected to the ERTA process, in which the substrates were manually overturned inside the vacuum chamber and raster scanned using an electron beam of 9 mA current at an accelerating voltage of 5 kV for 90 s. The ERTA was done in the presence of oxygen (3 N purity) in the chamber to maintain oxygen stoichiometry. A detailed discussion of ERTA technique was reported elsewhere (Gopalakrishnan et al 2011(Gopalakrishnan et al , 2012. Samples 'A' and 'B' after ERTA process are further referred to as samples 'A1' and 'B1', respectively.…”

“…In earlier reports, we have employed a quick and facile technique for the fabrication of Ni-WO 3 NWs and NSh using electron beam rapid thermal annealing (ERTA) process (Gopalakrishnan et al 2011(Gopalakrishnan et al , 2012. When comparing the time required for conventional annealing (*0.5-3 h), ERTA is much faster (*90 s) and easier method for inducing structural transformations and achieving rough surface with large surface area (Gopalakrishnan et al 2012).…”

“…When comparing the time required for conventional annealing (*0.5-3 h), ERTA is much faster (*90 s) and easier method for inducing structural transformations and achieving rough surface with large surface area (Gopalakrishnan et al 2012). This is rather a highly preferential technique for growing Ni-WO 3 NSs with good uniformity and repeatability.…”