Laser-ablated group IV metal atoms have been co-deposited at 11 K with water molecules in excess argon. The metal atoms reacted with water to form the insertion product HMOH and H 2 M(OH) 2 (M ) Ti, Zr, Hf) molecules spontaneously. Photolysis of the HTiOH species produced the H 2 TiO molecule as well as the TiO monoxide. In the cases of Zr and Hf, however, the H 2 ZrO and H 2 HfO molecules were produced on annealing, and the H 2 elimination process was not observed on photolysis. In addition, the HMO species were also observed and identified. The aforementioned species were identified via isotopic substitutions as well as theoretical frequency calculations. Qualitative analysis of the possible reaction paths leading to the observed products is proposed.

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The electrochemical and spectroelectrochemical properties of ZnO thin films prepared by reactive pulsed laser deposition in oxygen ambient have been investigated. The as-deposited and lithiated ZnO thin films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy techniques. The discharge and charge measurement indicates that the reversible capacities of the as-deposited ZnO thin-film electrodes are more than one Li per Zn atom with an initial capacity of less than 2.75 Li per Zn atom, and more than 0.75 Li per Zn atom could not be explained by the alloying process of ZnO reaction with Li. The evolution of the in situ absorbance spectra exhibits a marked boundary of lithiating 2Li per Zn atom and provides a hint about two different lithiation reactions occurring during charging of the ZnO/Li cell. A new reaction mechanism of lithium with ZnO involving both the classical alloying process and the oxidation/reduction of nanosized metal is proposed.

Nanocrystalline ZnFe 2 O 4 and Ag x ZnFe 2 O 4 (x ϭ 0.16, 0.37, 0.50) thin films have been prepared by reactive pulsed laser deposition, and used as anode materials for Li-ion batteries for the first time. X-ray diffraction ͑XRD͒ and scanning electron microscopy measurements showed that the prepared films were composed of a nanocrystalline structure with the average particle size less than 100 nm. The initial reversible capacity of ZnFe 2 O 4 and Ag 0.37 ZnFe 2 O 4 film electrodes reached 556 and 700 mAh/g, respectively, at a current density of 10 A cm Ϫ2 between 0.01 and 3.0 V. The Ag 0.37 ZnFe 2 O 4 film electrode exhibited better cyclability than ZnFe 2 O 4 film electrode, and retained 91% of the reversible capacity up to 100 cycles. According to our results on cyclic voltammetry of Li/ZnFe 2 O 4 cell coupled with ex situ photoelectron spectroscopy and XRD measurements of as-deposited and lithiated film electrodes, we suggest that the mechanism of ZnFe 2 O 4 film reacted with lithium involves reduction of Zn 2ϩ and Fe 3ϩ to metallic Zn and Fe 2ϩ , accompanying the formation of Li-Zn alloy. The dramatically improved electrochemical performance of Ag 0.37 ZnFe 2 O 4 film electrode might be related to the change of the reaction process after silver doping.

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