Preparation, oxidation and magnetic properties of FeCr ultrafine powders by hydrogen plasma-metal reaction

Particle features, oxidation behaviors and magnetic properties of ultrafine particles of Ni–Co alloy prepared by hydrogen plasma metal reaction

“…A broad and weak peak around 37 degrees is noticeable and suggests the presence of a certain amount of amorphous oxide, as observed in other metallic UFPs. 19,20 Table I summarizes characteristics of Ni-Co UFPs. The generation speed of UFPs varies from 10 to 16 g/h, among which one-third is collected in the collecting filter.…”

“…For the Fe and Ni based alloys, a fair linear relationship between ⌬M s (T)/M s (0) and T 3/2 is observed. 15,19 It seems that the temperature dependence of M s in the Co based UFPs is different from that in the Fe or Ni based UFPs. It can be seen that ⌬M s (T)/M s (0) gets smaller as the Co content is increased.…”

Formation and characterization of intermetallic Fe–Sn nanoparticles synthesized by an arc discharge method

“…4. Unlike FeeCo, FeeNi and FeeCr nanoparticles [20,21,4], the compositions of FeeSn nanoparticles are quite different from that of the corresponding bulk samples, which is little similar to the case in FeeAl nanoparticles [8]. As shown in Table 1, the mass ratios of Fe to Sn in nanoparticles are 79:21, 42:58, 28:72, and 14:86, which are markedly diverse in comparison to that in the corresponding bulks, which are 90:10, 70:30, 50:50, and 20:80, respectively.…”

“…However, it does not appear in sample (A), indicating that the Sn concentration is so low that it cannot be detected. The DSC curves of samples (C) and (D) show two strong exothermic peaks around 563 K and 692 K, respectively, and are associated with the oxidation of nanoparticles, phase transformation, and the growth of nanoparticles [4]. Generally, oxidation temperatures are lower than that of particle growth.…”

“…Generally, oxidation temperatures are lower than that of particle growth. Therefore, it is speculated that the peak at 563 K originates from the oxidation reaction of Sn and O 2 , which is higher than the 450 K oxidation temperature of pure Fe nanoparticles [4,26]. The DSC analysis implies that the existence of a single phase of Sn is present in the FeeSn nanoparticles.…”