WO3 thin films evaporated on unheated substrates were found to be substoichiometric and microcrystalline in nature as found by the ellipsometric studies, density, and porosity measurements. In this investigation, we measured the optical constants of WO3 thin films and of MxWO3 (M = H + , Li + , and Na + ) bronzes (with different concentrations, x) after being annealed at different temperatures over the range 298 to 453 K without and within an oxygen plasma environment using manual ellipsometry. It was found that the changes in film density and porosity of WO3 thin film when annealed at the temperature 413 K (without oxygen plasma) were not more than 3% and 12%, respectively, from the room temperature data. The thermo-optic coefficient (TOC) and electronic polarizability coefficient of WO3 thin film increased from 1.064 × 10 − 4 to 5.73 × 10 − 4 K − 1 and 0.1 × 10 − 26 to 0.3 × 10 − 26 cm3 K − 1, respectively, as a result of annealing the film at 413 K for 24 h. The samples HxWO3 (x = 0.172) and LixWO3 (x = 0.28, 0.332) upon annealing at 453 K (without and within oxygen plasma) over different annealing periods showed an increase in the TOC and in polarizability coefficients; as a result, the overall increase was from 0.15 × 10 − 4 to 8.7 × 10 − 4 K − 1 and 0.1 × 10 − 27 to 0.4 × 10 − 26 cm3 K − 1, respectively. By contrast, the samples H0.27WO3, Li0.125WO3, Na0.164WO3, and Na0.21WO3 attained negative TOCs after being annealed at 453 K over certain periods of time. In this case, the overall decrease in the TOC was from −0.9 × 10 − 4 to −6.7 × 10 − 3 K − 1, and the coefficient of temperature dependence of density decreased from −2.22 × 10 − 4 to −25.1 × 10 − 3 g cm − 3 K − 1. These new data were interpreted using different analytical models. Distinct annealing modes involve discrete chemical processes, and these processes were explained using separate chemical relations.

中文翻译：

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在无氧等离子体环境中和在氧等离子体环境中的退火钨青铜的热光学性质和电子极化系数的测量

通过椭圆光度法研究，密度和孔隙率测量发现，在未加热的基材上蒸发的WO3薄膜本质上是亚化学计量的和微晶的。在这项研究中，我们测量了WO3薄膜和MxWO3（M = H +，Li +和Na +）青铜（浓度不同，x）在298至453 K范围内的不同温度退火后的光学常数。使用手动椭圆偏光法在氧气等离子体环境中和没有氧气等离子体环境中进行操作。从室温数据发现，当在温度413K（没有氧等离子体）下退火时，WO3薄膜的膜密度和孔隙率的变化分别不大于3％和12％。WO3薄膜的热光系数（TOC）和电子极化系数从1.064×10-4增加到5。由于将薄膜在413 K下退火24小时，结果分别为73×10-4 K-1和0.1×10-26至0.3×10-26 cm3 K-1。HxWO3（x = 0.172）和LixWO3（x = 0.28，0.332）在不同退火时间在453 K（无氧等离子体内和在氧等离子体内）退火后，TOC和极化率系数均增加；结果，总体增加量分别为0.15×10-4至8.7×10-4 K-1和0.1×10-27至0.4×10-26 cm3 K-1。相比之下，样品H0.27WO3，Li0.125WO3，Na0.164WO3和Na0.21WO3在某些时间段内于453 K退火后达到负TOC。在这种情况下，TOC的总体下降从-0.9×10-4下降到-6.7×10-3 K-1，密度的温度依赖性系数从-2.22×10-4下降到-25.1×10 -3克厘米-3 K-1。这些新数据使用不同的分析模型进行了解释。不同的退火模式涉及离散的化学过程，并且使用独立的化学关系解释了这些过程。