Aerosol nanoparticles in the Fe1−xCrx system: Room-temperature stabilization of the σ phase and σ→α-phase transformation

Abstract

The production and structural characterization of gas-evaporated nanoparticles in the Fe 1−x Cr x system, with 0 Ͻ x Ͻ 0.83 are reported. The results show that for x ϳ 0.5 the metastable -FeCr can be stabilized and it constitutes up 60 wt % of the material. The sample with the highest -FeCr content is further analyzed to study the structural and the magnetic properties of this phase and its thermal stability. The -FeCr phase is weakly magnetic with an average magnetic moment of 0.1 B per Fe atom and a Curie temperature below ϳ60 K. It is stable up to 550 K where it starts to transform to bcc-FeCr. Annealing at 700 K yields Cr 2 O 3 due to Cr surface segregation and affects the magnetic behavior of the system, which is dominated by interparticle interactions.

Magnetic interaction reversal in watermelon nanostructured Cr-doped Fe nanoclusters

“…On the other hand, significant bcc a-FeCr phase formation at low Cr concentration (Cr < 13.6 at. %) was detected by Gich et al 8 and Racka et al 9 In our study, we observed that the r-phase formation begins at 2 at. % of Cr in core-shell iron/iron-oxide (Fe/Fe-oxide) NCs synthesized by cluster deposition method.…”

Structural and magnetic properties of bulk alloys and aerosol nanoparticles in the Fe100−xCrx system

“…doi:10.1016/j.jallcom.2005.08.046 tungsten spiral-basket-shaped filament heated by ac power in an Ar atmosphere at 3 Torr pressure. The details of the sample preparation technique were described elsewhere [8,9].…”

“…This study is aimed at complementing those previously reported in Refs. [8] and [9] on the same materials.…”

“…Shafranovsky). ticles display the metastable tetragonal sigma phase (-FeCr) coexisting with comparable volume fractions with the bcc one (␣-FeCr) [8,9]. The structural and magnetic properties as well as the thermal stability of Fe 52.…”

“…The structural and magnetic properties as well as the thermal stability of Fe 52. 3 Cr 47.7 nanoparticles with the highest content of the -phase were previously explored in detail [9].…”