Townrow S, Coleman P G
Department of Physics, University of Bath, Bath BA2 7AY, UK.
J Phys Condens Matter. 2015 Jun 10;27(22):225401. doi: 10.1088/0953-8984/27/22/225401. Epub 2015 May 18.
Changes in the structure of amorphous solid water films, grown by vapour deposition on a copper substrate at 75 K and then held at 120 K for 10 min to effect pore collapse, have been observed in the ranges 122-139 K and 150-162 K using positronium annihilation spectroscopy. It is proposed that the former is associated with the glass transition, with an effective activation energy of 0.266(3) eV. The data for the latter, which exhibit minima suggesting the temporary introduction of molecular disorder, can be processed to yield an effective activation energy of 0.47(2) eV, and are consistent with either a structural reorganization of the crystalline lattice or a relaxation of the amorphous structure mediated by defect migration.
通过在75K下气相沉积在铜衬底上生长，然后在120K下保持10分钟以使孔隙坍塌而形成的非晶态固体水膜的结构变化，已使用正电子湮没光谱法在122 - 139K和150 - 162K范围内观察到。有人提出，前者与玻璃化转变有关，有效活化能为0.266(3)eV。后者的数据呈现出最小值，表明暂时引入了分子无序，对这些数据进行处理可得到0.47(2)eV的有效活化能，并且与晶格的结构重组或由缺陷迁移介导的非晶态结构的弛豫相一致。
