Нанопроволоки из сплавов FeNi и FeCo: синтез, структура и мёссбауэровские измерения

Abstract

Nanowires (NWs) of FeNi and FeCo alloys were obtained by matrix synthesis based on galvanic filling of pores in track membranes. The change in the elemental composition of NWs when changing the composition of the electrolyte and when changing the deposition potential was studied. The effect of anomalous co-deposition of Fe is observed in the FeNi NWs: the iron content in the NWs is noticeably higher than that in the electrolyte. This difference increases when the initial concentration increases and when the growth potential decreases. An increase in the concentration of iron at the tops of the wires was also detected. For FeCo NWs, the composition corresponds to the composition of the electrolyte and did not change much when the potential changed. X-ray diffraction analysis allowed to determine the nature of changes in the spectra when the growth conditions change. The dependence of the X - ray spectra of FeNi on the growth potential is found- the intensity of the phase peaks changes. Mössbauer measurements revealed spontaneous magnetization for all samples of NW arrays along their axes. The dependence of the value of the ultrathin magnetic field Bh f on 57Fe nuclei on the composition of NWs (FexCo1−x and FexNi1−x) was obtained for the first time. It was found that the value of Bh f decreases with an increase in the speed of the electrodeposition process (or with an increase in the value of the deposition potential U).