Magnetic properties of the granular alloy Fe10Ag90 as a function of annealing temperature

Abstract

Fe10Ag90 granular alloys have been prepared using a sol-gel process, sintered at 300 °C and annealed at temperatures between 400 °C and 700 °C. The mean size of the iron particles, obtained from X-ray diffraction, is 30.0 ± 0.7 nm. Due to the existence of a distribution of particle sizes in these samples, both blocked (BL) and superparamagnetic (SPM) particles are present simultaneously, as confirmed by magnetization measurements at room temperature. AC susceptibility measurements as a function of temperature reveal a magnetic phase transition at about 770 °C, indicating the presence of particles exhibiting bulk behavior, in the samples annealed above 550 °C. The presence of these particles has been attributed to an atomic diffusion process between the grains, forming bulk-like multiple-domain Fe particles having Curie temperatures near that of bulk alpha-Fe phase (T C = 770 °C)

Dendritic Ag–Fe nanocrystalline alloy synthesized by pulsed electrodeposition and its characterization

“…This is due to the large positive heat of mixing, which is 42 kJ/mol in the solid state at equiatomic composition and 28 kJ/mol in liquid state [7]. Though this system has been prepared by a few methods such as magnetron sputtering, pulsed laser deposition, vapour quenching, sol-gel method, molecular beam epitoxy, etc., and its properties investigated [8][9][10][11][12], reports on its electrodeposition are scarce. The stability of electrodeposited Ag-Fe alloy has been reported by Roy et al [13].…”