X-ray absorption spectroscopy determination of the products of manganese borohydride decomposition upon heating
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Manganese borohydride Mn(BH4)2 powder is heated in a hydrogen atmosphere in vacuum. The long-range order in the structure is monitored in situ by means of X-ray absorption spectroscopy and X-ray diffraction; short-range order, via Mg K-edge X-ray absorption near-edge structure spectroscopy. Above 120°C, the X-ray diffraction pattern disappears and an irreversible phase transition occurs, accompanied by sample amorphization and profuse hydrogen desorption. In the hydrogen atmosphere, the phase transition occurs at a temperature of ∼110°C. The standard scheme of borohydride decomposition suggests hydrogen desorption and the formation of metallic manganese and boron. However, a theoretical analysis of X-ray absorption spectra shows that the most likely products of Mn(BH4)2 decomposition are manganese borides.
KeywordsBorohydride Hydrogen Desorption Diborane Metallic Manganese Irreversible Phase Transition
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- 6.Liu, R.X., Reed, D., and Book, D., J. Alloys Compounds, 2012, vol. 32, p. 515.Google Scholar
- 10.Liu, R., Reed, D., and Book, D., J. Alloys Compounds, 2012, vol. 32, p. 515.Google Scholar
- 17.Soloveichik, G.L., Mater. Matters, 2007, vol. 2.2, p. 11.Google Scholar
- 20.Bianconi, A, Dell Ariccia, M., Gargano, A., and Natoli, C.R., in Bond Length Determination Using XANES. EXAFS and Near Edge Structure, Bianconi, A., Incoccia, A., and Stipcich, S., Eds., Berlin: Springer, 1987, pp. 57–61.Google Scholar