On Hahn-echo measurements of short 29Si T2 times in some silica-based materials.
The Hahn-echo 29Si NMR experiments performed for determinations of T2 times in static supermicroporous materials SiO2-Al2O3-MnO and SiO2-MnO have shown the large loss in the echo intensity, observed at shortest echo delays. The relaxation patterns "intensity-tau", where the echo-intensity initially increases with increasing tau values and then it "normally" reduces due to spin-spin relaxation, are formally treated and discussed.
Bakhmutov
Vladimir I
VI
Department of Chemistry, Texas A&M University, College Station, TX 77842-3012, USA. bakhmoutov@mail.chem.tamu.edu