Mechanism of formation of Fe–N alloy in the solid-state reaction process between iron and boron nitride

Structural evolution of hexagonal BN and cubic BN during ball milling

“…The grain size of c-BN was kept in the range of 26-33 nm during ball milling, revealing that c-BN grains have not obviously refined due to its super-hardness. All the h-BN diffraction peaks, except the weak (0 0 2) peak, disappeared when the sample was milled for 24 h. Eventually the (0 0 2) peak of h-BN nearly disappeared after milling for 48 h. This phenomenon is similar to those happening in other systems during ball milling, such as Al-BN [8], Ti-BN [9], Fe-BN [10] and others. At the same time, except from the diffraction peaks of h-BN and c-BN, a diffuse peak appeared at the lower diffraction angle side of h-BN (0 0 2) during the disappearing of the h-BN (0 0 2) peak.…”

“…It has also been widely reported that the X-ray diffraction (XRD) peaks of one component disappeared quickly in the early stage of ball milling in many binary systems, especially in the systems containing a hexagonal crystalline component, such as Al-BN [8], Ti-BN [9], Fe-BN [10], Ti-C [11], W-MoS 2 [12] and W-C in our previous work. So far this phenomenon has been generally interpreted as crystallite refinement, formation of solid solution, amorphization.…”

Influence of heat of formation of B2/L12 intermetallic compounds on the milling energy for their formation during mechanical alloying

“…Portnoy et al [4] have shown in Ni-Al system that MA leads to the formation of the compound with the lowest free energy of formation. In contrast, Tao et al [5] have shown, in case of reactive milling of Fe-BN mixture, that the reaction is driven by activation barrier rather than the Gibb's free energy. However, from the classical nucleation kinetics formalism, it is known that the driving force for * Corresponding author.…”

11B nuclear magnetic resonance study of boron nitride nanotubes prepared by mechano-thermal method

“…A detailed inspection on the XRD patterns was firstly performed by checking the JCPDS cards and reveals a dominant BN phase and another impurities of a-Fe and iron compounds such as Fe 2 B, and Fe-N. And after, from the quantitative Rietveld analysis, 84.97 wt% graphitic boron nitride, 5.93 wt% hexagonal BNNT, 4.15 wt% a-Fe, 2.23 wt% Fe 2 B, and 2.72 wt% Fe-N could be, respectively, identified. These a-Fe and the Fe 2 B and the Fe-N appear to be incorporated and synthesized on the high-energy ball milling process and the annealing treatments for boron powder under N 2 gas environments, respectively [14,31]. In addition, the presence of these paramagnetic iron complexes was supported by electron paramagnetic resonance (EPR) spectroscopy at room temperature ( Fig.…”

“…The EPR signal can be fitted with the derivative functions consisting of one Lorentzian and two Dysonians [32]. The Lorentzian line has gZ1.98 (G0.01) and DH fwhm Z730(G60) G and the Dysonian 1 can be described with gZ2.48(G0.05) and DH fwhm Z925 (G69) G, and the Dysonian 2 has gZ5.00(G0.1) and DH fwhm Z2491(G90) G. Here, we assigned the Lorentzian (gZ1.98) to the soft magnetic Fe 2 B [31,33], the Dysonian 1 (gZ2.48) to the metallic a-Fe [34], and the Dysonian 2 (gZ5.00) to the magnetic Fe-N [31,35]. In results, one can notice that the observed stretched-exponential relaxations are attributed to the paramagnetic a-Fe, Fe 2 B, and Fe-N.…”