17 research outputs found
Mossbauer-spectra of Some Low Symmetry Compounds Containing a Tin Manganese Bond
info:eu-repo/semantics/publishe
The A1 Pillaring of Clays .1. Pillaring With Dilute and Concentrated A1 Solutions
Saponite, hectorite, and laponite have been pillared with cationic Al clusters, and special attention has been given to the solution chemistry of Al. Pillared saponite is obtained after exchange with refluxed Al solutions; while for hectorite, Al solutions treated with ammonium acetate give a pillared product with 1.8-1.9 nm spacing and thermal stability up to 873 K. In both types of solutions, the Keggin ion Al cluster is a minority species or totally absent. The typical 1.8-1.9 nm spacing is only obtained after washing. The quality of the pillared material can be judged From its thermal stability, its surface area, and the width of the d001 line before and after pillaring. The width should not exceed 0.3 nm before calcination and 0.5 nm after calcination. The latter criterion reflects the importance of the crystallinity of the parent clay for successful pillaring. Pillaring in concentrated conditions occurs by a combination of ion exchange and precipitation of Al and gives materials that exhibit poor thermal stability
Polymorphous/crystalline single heterojunction and double heterojunction solar cells optimisation on p type monocrystalline silicon
International audienc
Silicon heterojunction solar cells : surface passivation quality on large area n type and p type monocrystalline silicon, effect on solar cell efficiency
International audienc
Polymorphous/crystalline single heterojunction and double heterojunction solar cells optimisation on p type monocrystalline silicon
International audienc
Polymorphous/crystalline silicon heterojunction solar cells : optimization on monocrystalline silicon
International audienc