Raman spectra of hot-pressed boron suboxide

Ronald Machaka1, 2*, Bonex W. Mwakikunga3, 4, Elayaperumal Manikandan5, Trevor E. Derry1,6, Iakovos Sigalas1, 2

1DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Private Bag 3, Wits, Johannesburg 2050, South Africa

2School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Private Bag 3, Wits, Johannesburg 2050, South Africa

3CSIR National Laser Centre, P.O. Box 395, Pretoria 0001, South Africa

4Department of Physics and Biochemical Sciences University of Malawi, The Polytechnic Private Bag 303, Chichiri, Blantyre 0003 Malawi

5CSIR National Centre for Nano-Structured Materials, P.O. Box 395, Pretoria 0001, South Africa

6School of Physics, University of the Witwatersrand, Private Bag 3, Wits, Johannesburg 2050, South Africa

Adv. Mater. Lett., 2012, 2 (1), pp 58-64

DOI: 10.5185/amlett.2010.9167

Publication Date (Web): Apr 08, 2012

E-mail: ronald.machaka@wits.ac.za

Abstract


Despite hot pressing being the most popular method of consolidating B6O powder, the Raman spectrum of polycrystalline hot-pressed B6O was until now poorly understood. Yet, recent reports have contributed to the understanding of only high-pressure and high-temperature sintered B6O. Using an automated method for subtraction of the fluorescence background from Raman measurements, the first- and second-order Raman spectra of B6O and their dependence on the wavelength of the excitation line from a green Argon ion (Ar+) laser are reported. Our results confirm the existence of observable highly resolved first- and second-order Raman modes measured at ambient conditions using a green Ar+ ion laser as the source of excitation. We also extend our study to present a comparative analysis of our recovered first-order Raman spectra and previously reported first-order Raman spectra other α-rhombohedral boron type based ultra-hard boron-rich ceramic materials. The results show an overall good agreement.

Keywords

Hot-pressed boron suboxide, B6O, Raman spectroscopy, fluorescence background subtraction

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