Papers by Keyword: Nanocrystalline Films

Abstract: This paper introduces a novel process for growing one-dimensional nanomaterials. That is, firstly, preparing a pure metal nanocrystalline film by using pulse electro-deposition, then, using this film as a catalyst for synthesizing variant one-dimensional carbon nanomaterials and one-dimensional metal oxide nanoneedles. Comparing with the nanoparticle catalyst, the growth mechanism of the present one-dimensional nanomaterials belongs to the “base growth model”, and it has advantages such as a much simpler process and no post purification requirement. In addition, the present method provides a possibility for diameter control of the one-dimensional nanomaterials through grain size control of the nanocrystalline film by adjusting the pulse electro-deposition parameters.

Abstract: Data on the random magnetic anisotropy and exchange correlation length in soft magnetic nanocrystalline Fe79Zr10N11 films were obtained using a calculation technique in frame of the random magnetic anisotropy model. The calculations are performed using approach magnetization to saturation curves. The local magnetic anisotropy fields (Ha), and magnetic anisotropy correlation radii (Rс) reduced to =(A/K)1/2 were determined for the films annealed at 475 and 6000 C for 0.5, 1, 2, and 3 h. The correlation Hc ~(Rc/)3 for the all annealed films was found.

Abstract: Nanocrystalline vanadium oxide thin films have been deposited by reactive DC magnetron sputtering onto glass substrates under different processing conditions. Structural analysis and phase identification have been carried out by means of X-ray diffractometry (XRD). The surface morphologies of the different films have been examined by both scanning electron microscopy (SEM) and atomic force microscopy (AFM). The XRD results revealed single and multiple phase oxides such as VO2(B), VO2(M), V2O5, etc. with considerable differences concerning to surface morphologies, as observed by SEM and AFM. The effects the O2/Ar flow ratio, DC current, and working pressure on the phases formed and growth rates is discussed. Moreover, VO2(M) films exhibited different morphologies concerning to grain size and shape as well as dissimilar preference in crystal orientation, as a result of the processing conditions. The optical/thermochromic response of the VO2(M) specimens deposited under different growth rate conditions was evaluated by optical spectrophotometry and related to the respective structural characteristics.

Abstract: The paper presents the study of CdS0.2Se0.8 n-type films 0.50-0.65 µm thick manufactured by the RF sputtering technique and their electro-optical properties. The effects of the substrate texturing on the structure and properties of the films are discussed. Recrystallization of the films sputtered onto glass substrates coated with a continuous or island-like silver sublayer resulted in the formation of a nanosized grain structure with higher photosensivity than films deposited onto aluminium oxide ceramics.