Synthesis and Comparison of Boron Nitride Nanostructure Prepared on Silicon and Molybdenum Substrates by Laser Plasma De
- PDF / 688,121 Bytes
- 9 Pages / 612 x 792 pts (letter) Page_size
- 82 Downloads / 159 Views
Synthesis and Comparison of Boron Nitride Nanostructure Prepared on Silicon and Molybdenum Substrates by Laser Plasma Deposition Technique M. Sajjad, H. X. Zhang, and P. X. Feng* Department of Physics, University of Puerto Rico,
P.O. Box 70377, San Juan, PR 00936-8377 USA ABSTRACT The synthesis of boron nitride nanowires on silicon (Si) and nanorods on molybdenum (Mo) substrates at the same experimental conditions was composed. Fine tip nanowires with diameters around 50 nm were produced on Si substrates, whereas, nanorods with diameter around 100 nm were formed on Mo substrates. The change in length from 5 µm to 100 µm for nanowires and 0.2 µm to 0.8µm for nanorods following variation of substrate temperature were studied systematically. Scanning Electron Microscopy was used to analyze the surface images of BN nanowires and nanorods. Energy Dispersive X-Ray spectroscopy (EDS) was used to analyze boron and nitrogen concentration in the samples. The crystal structures of BN samples were investigated using Raman spectroscopy and x-ray diffraction. The experimental results showed that the nanorods are hexagonal mixed with cubic, whereas the nanowires are hexagonal.
*Corresponding author: E-mail: [email protected] (P. X. Feng)
INTRODUCTION In the past few years, considerable efforts have been placed in material research on nucleation of novel one-dimensional nanostructures. A significant breakthrough was in synthesizing boron nitride (BN) [1] nanowires and nanorods. Boron nitride is a wellknown wide band gap semiconductor with excellent properties for devices operating under extreme conditions such as high temperature, high power, and high frequency, which make it a promising material for the electronic devices [2,3]. For example, our preliminary results indicate that diamond was completely destroyed after 5 hours of annealing at 9000C in air, whereas the BN crystal structure remained unchanged. Boron nitride (BN) exhibits superior properties (greater chemical stability and tunable electronic and sensing properties) vs. bulk BN and has potential applications in electronic devices [4]. There is a significant interest in the synthesis of nanostructured BN including nanosheets, nanowires, nanorods and so on as novel functional materials for nanoscale engineering [5]. The mechanical and electrical properties can be useful if long nanowires and nanorods can be synthesized. However, synthesis of long onedimensional, super-thin nanoscale materials is still a challenge. Recently, various techniques have been used for the synthesis of boron nitride nanowires and nanorods, including arc discharges [6], laser ablation [7], ball-milling [8], plasma jet [9], and substitution reactions in chemical vapor deposition (CVD) [10]. Most of these synthesis methods were carried out at very high temperature (1100 0C to 2700 0C), and contained undesirable impurities in the samples. In order to get nanostructure with fewer impurities, several approaches have been proposed recently to synthesize nanostructure at temperature lower
Data Loading...
