Infrared reflectance studies of hillock-like porous zinc oxide thin films

Microstructure evolution of Al-doped zinc oxide and Sn-doped indium oxide deposited by radio-frequency magnetron sputtering: A comparison

“…When the film becomes thicker, hillock-like features grow along the h0001i direction on the first smooth layer. The hillock structures have been reported for ZnO or doped-ZnO by magnetron sputtering, 19 PLD9, MOCVD, 20 and vapor phase transport process. 21 The hillock density increases with increasing film thickness, i.e., 4.4%, 11.7% and 29.2% for 52 nm, 105 nm, and 210 nm thick films, respectively.…”

Effect of Porosity on the Infrared Radiative Properties of Plasma-Sprayed Yttria-Stabilized Zirconia Ceramic Thermal Barrier Coatings

“…Some of these effective approximations have already been applied for modeling the infrared reflectance spectra of textured media. − Certain authors combined the effective medium theories together with the optical response of thin films in the visible and near IR spectral ranges to obtain the nanometric porosity and/or thickness of thin films using ellipsometry and/or IR spectroscopy. , The same idea has already been applied in the mid-infrared for estimation of the porosity of nanometric thin and nonscattering films. , …”

“…18,19 The same idea has already been applied in the mid-infrared for estimation of the porosity of nanometric thin and nonscattering films. 20,21 The aim of this work is to prove the viability of using these kinds of approaches in the far-infrared spectral region for characterizing thicker ceramic films with higher porosity and roughness characteristic sizes, as found in thermal barrier coatings. To our knowledge, this is the first time that the semitransparent far-infrared spectral region is used to characterize the porosity of rough ceramic plasma-sprayed coatings, which are some tens of micrometers thick and whose mean pore size is about several hundred nanometers.…”