Institut für Festkörperphysik, Technische Universität Darmstadt, Hochschulstr. 6, 64289 Darmstadt, Germany.
Phys Chem Chem Phys. 2013 Jan 14;15(2):576-80. doi: 10.1039/c2cp43543h. Epub 2012 Nov 26.
The high-frequency reorientation dynamics of O-(2)H bonds is investigated in various amorphous ices including eHDA (expanded high density amorphous ice), LDA-II (low density amorphous ice II) and HGW (hyperquenched glassy water) using (2)H-NMR spin-lattice relaxation as a local probe. Both low density forms, HGW and LDA-II, show similar spin-lattice relaxation but differ in the thermal stability with respect to the transition into crystalline cubic ice I(c). HGW already transforms slightly above 135 K whereas LDA-II crystallizes at 150 K. eHDA is distinguishable from other high density amorphous ices in its thermal stability and spin-lattice relaxation. Its relaxation times are much larger compared to those of VHDA (very high density amorphous ice) and uHDA (unrelaxed high density amorphous ice). eHDA does not show annealing effects, transforms sharply into LDA-II above 123 K and provides higher thermal stability as compared to other high density forms.
使用（2）H-NMR 自旋晶格弛豫作为局部探针，研究了各种非晶冰（包括 eHDA（扩展高密度非晶冰）、LDA-II（低密度非晶冰 II）和 HGW（超淬火玻璃水））中 O-(2)H 键的高频重定向动力学。两种低密度形式 HGW 和 LDA-II 显示出相似的自旋晶格弛豫，但在转变为立方冰 I(c)时的热稳定性不同。HGW 在略高于 135 K 时就已经发生转变，而 LDA-II 在 150 K 时结晶。与其他高密度非晶冰相比，eHDA 在其热稳定性和自旋晶格弛豫方面表现出不同。与 VHDA（非常高密度非晶冰）和 uHDA（未弛豫高密度非晶冰）相比，其弛豫时间要长得多。eHDA 没有退火效应，在 123 K 以上急剧转变为 LDA-II，并提供比其他高密度形式更高的热稳定性。
