Mechanical spectroscopy observation of LiAlH4 decomposition

I haven't seen this posted before. Unfortunately the article is not open access.

Mechanical spectroscopy observation of LiAlH₄ decomposition

Enrico Gianfranco Campari, Ennio Bonetti, Angelo Casagrande, Loris Ferrari, Giuseppe Levi

https://doi.org/10.1016/j.jallcom.2019.152242

Quote from Abstract

Dynamic elastic modulus and internal friction of cold consolidated mixtures of Al and LiAlH₄ powders have been measured. All reactions and decompositions occurring in LiAlH₄ during a thermal run have been detected as dynamic elastic modulus anomalies and internal friction peaks, proving the effectiveness of mechanical spectroscopy for the study of alanate. These informations are complementary to calorimetric and thermogravimetric data.

Quote from Highlights

• Dynamic elastic modulus and internal friction of cold consolidated mixtures of Al and LiAlH₄ powders have been measured.
• LiAlH₄ decomposition detected by means of mechanical measurements.
• Complementarity of calorimetry and mechanical spectroscopy for the study of alanate.

Alan Smith

Thanks. I've read it earlier, but wasn't sure whether I could put it on the forum since it's paywalled.

The authors consolidated (cold-pressed) at 1 Gpa pressure (which should be equivalent to about 10 tons/cm²) mixtures composed of 200–350 mg Al + 40–60 mg LiAlH₄ material (Alfa Aesar, used as-received) into 1 mm-thick bars and ran in addition to the usual differential scanning calorimetry studies also mechanical measurements measuring their internal stress (as far as I understand) as they were heated. It turns out that changes on this regard are also related to the decomposition and transformations of the LiAlH₄ into other phases, so they can be considered a novel way of studying the decomposition steps of LiAlH₄ which could be used in addition to calorimetry.

Of possibly more relevance to LENR, it appears that following decomposition at a heating rate of 3–5K/min, the so-formed bars after the first decomposition step of LiAlH₄ become rich of pores and crack features. Furthermore these bars do not show the typical endothermic response just before such first decomposition step of LiAlH₄. Heat treatment above 700K may remove such defect network, at least in the case of pure Al powders.

I haven't read any direct suggestion of anomalous heating effects, which is a bit of a disappointment given the authors. If there is, it's obfuscated in the text or data. It could be that I need to read the paper more carefully.