Paper Title:
The Effects of Oxidized and Oxide-Free Boron on the Mg-B-H Nanohydrides Transformation in the Nearly Nanosized Powders
  Abstract

In this work oxidized and oxide-free amorphous boron (a-B) powder and elemental Mg were used in an attempt to directly synthesize the Mg(BH4)2 complex hydride by controlled reactive mechanical alloying (CRMA) under hydrogen in a magneto-mill up to 200h. The particle size was refined to the 100-200nm range. Nanocrystalline MgH2 (~6nm crystallite size) was formed within the particles when an oxidized a-B is used. In contrast, a mixture of MgB2 and an amorphous hydride MgHx was formed when an oxide-free a-B was used. Differential scanning calorimetry (DSC) test up to 500°C produced a single endothermic heat event at 357.7°C due to hydrogen desorption. In addition, desorption conducted in a Sieverts-type apparatus revealed ~1.4wt.% of hydrogen release. The X-ray diffraction pattern after DSC test of the 200h milled sample made with oxide-free boron showed the presence of MgB2.

  Info
Periodical
Solid State Phenomena (Volume 128)
Main Theme
Edited by
Witold Łojkowski and John R. Blizzard, Urszula Narkiewicz and Janusz D. Fidelus
Pages
47-52
DOI
10.4028/www.scientific.net/SSP.128.47
Citation
R.A. Varin, C. Chiu, Z. S. Wronski, A. Calka, "The Effects of Oxidized and Oxide-Free Boron on the Mg-B-H Nanohydrides Transformation in the Nearly Nanosized Powders", Solid State Phenomena, Vol. 128, pp. 47-52, 2007
Online since
October 2007
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Shan Gao, Jing Feng Wang, Pei Dao Ding, Fu Sheng Pan, Ai Tao Tang
Abstract:Cycle capacities of Amorphous Mg-Ni alloys declined so fast therefore they can’t be used practically. In this paper,the influence of adding...
234
Authors: Ge Wang, Chun Zhang, Yu Ying Zhu, Zhi Gang Chao, Qiang Li
Abstract:Ti50Fe45Sn5 amorphous alloys powder was prepared by mechanical alloying (MA) in a high-energy planetary ball mill. The non-crystallization...
104
Authors: Petr Urban, Francisco Gomez Cuevas, Juan M. Montes, Jesus Cintas
Chapter 8: Metals and Alloys
Abstract:The amorphization process by mechanical alloying in the Fe-Si alloy system has been studied. High energy ball milling has been applied for...
739
Authors: G. Kőrösy, K. Tomolya, Dóra Janovszky, Jenő Sólyom
Abstract:There is an active research work in the field of amorphous alloys since the discovery of metallic glasses, half a century ago [. In contrast...
419
Authors: Y.B. Yuan, Rui Xiao Zheng, Su Jing Ge, Han Yang, Chao Li Ma
Abstract:Al86Ni7Y4.5Co1La1.5 (at.%) alloy powder was produced by argon gas atomization process....
281