Wells Matthew P, Bower Ryan, Kilmurray Rebecca, Zou Bin, Mihai Andrei P, Gobalakrichenane Gomathi, Alford Neil McN, Oulton Rupert F M, Cohen Lesley F, Maier Stefan A, Zayats Anatoly V, Petrov Peter K
Opt Express. 2018 Jun 11;26(12):15726-15744. doi: 10.1364/OE.26.015726.
Materials such as W, TiN, and SrRuO (SRO) have been suggested as promising alternatives to Au and Ag in plasmonic applications owing to their stability at high operational temperatures. However, investigation of the reproducibility of the optical properties after thermal cycling between room and elevated temperatures is so far lacking. Here, thin films of W, Mo, Ti, TiN, TiON, Ag, Au, SrRuO and SrNbO are investigated to assess their viability for robust refractory plasmonic applications. These results are further compared to the performance of SrMoO reported in literature. Films ranging in thickness from 50 to 105 nm are deposited on MgO, SrTiO and Si substrates by e-beam evaporation, RF magnetron sputtering and pulsed laser deposition, prior to characterisation by means of AFM, XRD, spectroscopic ellipsometry, and DC resistivity. Measurements are conducted before and after annealing in air at temperatures ranging from 300 to 1000° C for one hour, to establish the maximum cycling temperature and potential longevity at elevated temperatures for each material. It is found that SrRuO retains metallic behaviour after annealing at 800° C, while SrNbO undergoes a phase transition resulting in a loss of metallic behaviour after annealing at 400° C. Importantly, the optical properties of TiN and TiON are degraded as a result of oxidation and show a loss of metallic behaviour after annealing at 500° C, while the same is not observed in Au until annealing at 600° C. Nevertheless, both TiN and TiON may be better suited than Au or SRO for high temperature applications operating under vacuum conditions.
诸如W、TiN和SrRuO（SRO）等材料，因其在高温工作条件下的稳定性，被认为是等离子体应用中Au和Ag颇具前景的替代材料。然而，目前尚缺乏对室温与高温之间热循环后光学性质再现性的研究。在此，对W、Mo、Ti、TiN、TiON、Ag、Au、SrRuO和SrNbO薄膜进行研究，以评估它们在坚固的难熔等离子体应用中的可行性。这些结果进一步与文献中报道的SrMoO的性能进行比较。通过电子束蒸发、射频磁控溅射和脉冲激光沉积，在MgO、SrTiO和Si衬底上沉积厚度在50至105nm之间的薄膜，然后通过原子力显微镜（AFM）、X射线衍射（XRD）、光谱椭偏仪和直流电阻率进行表征。在300至1000°C的空气中退火1小时前后进行测量，以确定每种材料在高温下的最高循环温度和潜在寿命。结果发现，SrRuO在800°C退火后仍保持金属行为，而SrNbO在400°C退火后发生相变，导致金属行为丧失。重要的是，TiN和TiON的光学性质因氧化而退化，在500°C退火后表现出金属行为丧失，而Au直到600°C退火才出现这种情况。尽管如此，在真空条件下运行的高温应用中，TiN和TiON可能比Au或SRO更适合。
