Hiller M, Lavrov E V, Weber J
Technische Universität Dresden, 01062 Dresden, Germany.
Phys Rev Lett. 2007 Feb 2;98(5):055504. doi: 10.1103/PhysRevLett.98.055504. Epub 2007 Jan 30.
Ortho-para conversion of isolated interstitial H2 in single-crystalline Si is studied by Raman scattering. This process is suggested to be caused by the interaction of H2 with the nuclear magnetic moment of 29Si. At 77 K the ortho-to-para conversion rate is approximately 0.015 h(-1) for all Si samples employed in the experiments. At 300 K, the reverse para-to-ortho transition is observed. It occurs with a rate of roughly 0.18 h(-1) and results in a thermodynamically nonequilibrium ortho-para ratio.
