Создание спин-инжекторного источника терагерцового излучения на основе массива нанопроволок из ферромагнитных металлов
A model of inhomogeneous pores filling during electrodeposition of ordered metal nanowire arrays isdeveloped. The model takes into consideration the ionic transfer both in the varying diffusion layer in thepores and in the diffusion layer above the template, which is determined by the external hydrodynamicconditions. The model takes into account the kinetics of electrochemical reaction (the Tafel equation)and the diffusion transfer of metal cations both in the pores and in the outer diffusion layer. In the quasi-steady-state approximation, two problems were considered. The problem for the case that the initiallength of one pore differs from that of all other pores is solved analytically. The problem for the case thatthe initial lengths of all pores are different is solved numerically. The time dependences of unfilled porelength are obtained for various overpotentials and various initial distributions of pore length. It is foundthat the pores filling inhomogeneity increases with increasing overpotential.
A simple model of electrochemical growth of nanowires in the pores of anodic aluminum oxide (AAO) template is developed. The metal deposition is considered at various overpotentials. The model takes into consideration the ionic transfer both in the varying diffusion layer in the pores and in the diffusion layer above the template, which is determined by the external hydrodynamic conditions. The model takes into account the kinetics of electrochemical reaction by means of the Tafel equation and the diffusion transfer of metal cations both in the pores and in the outer diffusion layer. The analytical solution of the problem with several simplifications yields the equations for calculating the time dependence of current, the pore filling time, and other parameters of the process. An example of the application of the model for the analysis of nanowire growth in the template pores is compared with the experimental data showing good agreement.
We developed the model of the internal phonon bottleneck to describe the energy exchange between the acoustically soft ultrathin metal film and acoustically rigid substrate. Discriminating phonons in the film into two groups, escaping and nonescaping, we show that electrons and nonescaping phonons may form a unified subsystem, which is cooled down only due to interactions with escaping phonons, either due to direct phonon conversion or indirect sequential interaction with an electronic system. Using an amplitude-modulated absorption of the sub-THz radiation technique,we studied electron-phonon relaxation in ultrathin disordered films of tungsten silicide.We found an experimental proof of the internal phonon bottleneck. The experiment and simulation based on the proposed model agree well, resulting in τe−ph ∼ 140–190 ps at TC = 3.4K, supporting the results of earlier measurements by independent techniques.