Solid nitrogen in nanopores at high pressure: A phase transition in the amorphous layers - art. no. 052105

The vibrational spectrum of confined N-2 has been studied by Raman spectros copy at room temperature as a function of pressure in the fluid, the beta p hase and the delta phase, in pores with 62. 31. 17, and 3.2 Angstrom radii. In the pores with radius of 17 Angstrom a discontinuity has been observed in the vibrational frequencies of N-2 in the adsorbed amorphous phase, sugg esting a phase transition. It occurs at the fluid-solid transition of the b ulk. Further, for the largest matrix, the solid-solid transition takes plac e in a wide pressure interval of about 1 GPa.