Nanosized Rutile (TiO2) Thin Film upon Ion Irradiation and Thermal Annealing
Nanosized Rutile (TiO2) Thin Film upon Ion Irradiation and Thermal Annealing
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DOI：
10.1021/jp2056283
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发表时间：
2011-10
影响因子：
3.7
通讯作者：
Jiaming Zhang;J. Lian;F. Namavar;Jianwei Wang;H. Haider;K. Garvin;R. Ewing
中科院分区：
文献类型：
--
作者：
Jiaming Zhang;J. Lian;F. Namavar;Jianwei Wang;H. Haider;K. Garvin;R. Ewing
在三种 TiO2 多晶型中，当晶体尺寸约为 10 nm 时，金红石与锐钛矿和板钛矿相比热力学不稳定。在这项研究中，通过离子束辅助沉积（IBAD）在薄膜几何形状中合成了平均晶粒尺寸为∼6 nm的纳米晶金红石，并在金红石薄膜和硅衬底之间具有非晶态TiO2夹层。沉积过程中高强度离子轰击产生的非化学计量可能在纳米尺度上稳定了亚稳态金红石相。通过 1 MeV Kr2+ 辐照结合热退火研究了纳米金红石的相稳定性。原位透射电子显微镜（TEM）结果表明，在室温辐照时，纳米晶金红石发生部分非晶化，而在573 K辐照时纳米晶保持稳定。在573 K下，非晶态TiO2发生离子束诱导再结晶，明显低于热诱导再结晶温度。
Among three TiO2 polymorphs, rutile is thermodynamically unstable as compared with anatase and brookite when the crystal size is ∼10 nm. In this study, nanocrystalline rutile with an average grain size of ∼6 nm was synthesized in a thin film geometry by ion beam-assisted deposition (IBAD) with an amorphous TiO2 interlayer between the rutile film and Si-substrate. Nonstoichiometry produced by high-intensity ion bombardment during deposition may have stabilized the metastable rutile phase on the nanoscale. The phase stability of nanosized rutile was investigated by irradiation using 1 MeV Kr2+ combined with thermal annealing. In situ transmission electron microscopy (TEM) results indicate that partial amorphization occurred in nanocrystalline rutile when irradiated at room temperature, whereas the nanocrystals remained stable upon irradiation at 573 K. Ion beam-induced recrystallization occurred in the amorphous TiO2 at a 573 K, significantly lower than the temperature for thermally induced recrystallizatio...