We have previously reported the successful fabrication of electro

We have previously reported the successful fabrication of electrodes on a bismuth nanowire encased in a quartz template by utilizing a combination of chemical mechanical

polishing (CMP) and focused ion beam (FIB) processing. The resistivity of the bismuth nanowire was thereby successfully measured using the four-wire selleck inhibitor method [32]. As a next step, a technique for exposure of the bismuth nanowire for Hall measurements was also developed [33]. Many researchers have reported the resistivity of bismuth nanowires measured using the two-wire method due to difficulty of electrode fabrication with the four-wire method; however, the four-wire method is theoretically more suitable for estimation of the resistivity. There have been some results C59 wnt chemical structure reported for the resistivity measured using the four-wire method; however, the surface of bismuth nanowires is oxidized

during the fabrication process, which makes it difficult to fix the boundary conditions for the wire diameter direction [12–14]. Furthermore, it was reported that a majority of the bismuth nanowire becomes amorphous due to irradiation with a high-energy gallium (Ga) ion beam during FIB processing [13]. Therefore, it would be difficult to successfully apply FIB processing to a bare bismuth nanowire. However, the bismuth nanowires prepared in our work were completely encased in a quartz template. Therefore, the influence of Ga ion beam irradiation could be neglected if the exposed area was very small with respect to the entire surface of the bismuth nanowire. The FIB processing technique was applied to fabricate electrodes on a 521-nm-diameter bismuth nanowire for Hall measurements, and the electrodes were evaluated to confirm a suitable contact.

Furthermore, the temperature dependence of the resistivity was measured with comparison of the two-wire and four-wire resistance measurements. To confirm the validity of the electrode fabrication technique to estimate the Hall coefficient, Hall measurements were performed using a 4-μm-diameter bismuth microwire. It would be ideal to use a nanometer-order diameter wire to demonstrate the Hall measurement; however, verification with a 4-μm-diameter tuclazepam microwire was performed first, which is predicted to give almost the same Hall coefficient as that of the bulk. We discuss the adequacy of the electrical Momelotinib order contacts on the bismuth nanowires for resistivity and Hall measurements. Methods Figure 1a shows a schematic diagram of the configuration used for Hall measurements of bismuth nanowires. Although electrodes are required on the side surfaces of the bismuth nanowire for Hall measurements, these bismuth nanowires are covered with the quartz template, as shown in Figure 1a.

Comments are closed.