K L Chopra Thin Films Phenomena Mcgraw Hill Book Pdf30/11
K L Chopra Thin Films Phenomena Mcgraw Hill Book Pdf
we investigate the thermally activated metal diffusion (tamd) of tetragonal ti in the unstrained ultrathin film (≤1 nm) deposited on the (001) crystalline silicon substrate. the tamd conductivity based on the aizu model is found to be much lower than the one expected by the ith*-order temperature-dependent activation energy (ei): we also find that the ith*-order activation energy for the diffusion may not be the same for the ith*-order alloy and for the single-element diffusion. we finally discuss the possible origin of the observed difference in activation energies.
2d diffraction at thicknesses in the order of micrometers or larger is generally thought to be observed as so-called speckle patterns (pohl &amp; yee, 2010 ). speckle patterns were observed in xrr for all three films, even when the same scan (number of repeated measurements, object size and incident x-ray energy) was applied. however, only films grown at 400k are discolored, as shown in fig. 2. this might be a result of gas evolution due to increased film growth rate and mobility at higher substrate temperatures. the discoloration decreases during post-annealing, most likely due to the molecular desorption that leads to a reduction in gas pressure as the surface tension decreases with reduced gas content. theoretical modeling of xrr data requires a detailed calculation of the extinction factors of the material and the substrate. these factors are particularly large in the case of 2d-powder xrr, as is the case for our experiments. we recently published a detailed description of the extinction factors of cupc and its isostructural polymorphs (grossvogel &amp; hinsch, 2018 ). the value of the extinction factors is generally determined by the fourier transformation of measured xrr data, which is an inverse measurement, a simulation of which requires the assumption of an appropriate model. the simulation of an xrr profile from a real surface is accomplished by processing the measured data with, e.g., a lorentz model, which assumes an absorptive medium with well-defined scalar components and pre-defined attenuation and extinction coefficients (fig. 6 ). these coefficients are measured for every material and are usually prepared for smooth surfaces. however, due to the low absorption of the powder film material in our case, the lorentz model cannot be applied; instead, we have to make use of the grasp matlab map (freiberger & cox, 1995 ) or other parameters have to be adjusted to account for the real geometry of the powder layer, which we describe next.