Synthesis of Metastable Fe₃C, Co₃C and Ni₃C by Mechanical Alloying Method

Controlled synthesis and magnetic properties of hard magnetic CoxC (x=2, 3) nanocrystals

“…Tokumitsu [14] found that the Co 3 C prepared by mechanical alloying method has a phase decomposition at temperatures between 468 and 524 1C (determined by DSC), and the decomposition temperature varied with heating rate; the decomposition temperature becomes lower with decreasing heating rate. This thermal instability may provide an alternative method for fabrication of cobalt nanoparticles and granular films.…”

“…To verify this conjecture, the cobalt carbide nanoparticles were annealed in vacuum at 773 K for 30 min, then the XRD result showed that the obtained sample after the annealing was the mixture of cobalt and graphite. This thermal process can be expressed as the following equations [14]:…”

“…However less report can be found in studies of their magnetic properties. In the previous reports, Co 3 C was synthesized by mechanical alloying method with precursors of cobalt and carbon powders [14]. Co-C granular films and Co 2 C thin film were fabricated via electron beam evaporation and chemical vapor deposition [12,15], respectively.…”

Microstructure characterization of nanocrystalline Fe3C synthesized by high-energy ball milling

“…If the Fe-C system is composed of a very fine microstructure, which can be synthesized by MA, it is possible to produce an advanced material with high hardness, wear resistance, toughness and good magnetic properties. Four types of solid state reactions at the initial stage of MA of mixture Fe 100−x C x with x ≤ 33% were suggested in the recent publications: (i) formation of martensite like interstitial solid solution of C in Fe [1,6,7], (ii) simultaneous formation of the Fe 3 C carbide and some hexagonal carbides [1,8,9], (iii) formation of Fe 3 C only [10][11][12][13] and (iv) formation of the amorphous Fe-C phase prior to the formation of the Fe 3 C carbide [14][15][16][17][18]. Penetration and segregation of C atoms along the Fe grain boundaries and formation of Fe-C amorphous phase in the interface regions were also reported [19][20][21][22] for the mixtures with x = 20-25%.…”

First‐Principles Study of Structure, Magnetic Properties, and Stability of η‐Carbides (M,Fe)3W3C (M = Ti, V, Cr, Mn, Co, and Ni)

“…The formation energies of (M,Fe) 3 W 3 C, as well as those of MC, M 2 C, M 5 C 2 , M 7 C 3 , M 3 C, M 6 C, and M 23 C 6 are presented in Figure 1. There is no binary M x C y carbide that would be stable for any M, whereas all η-carbides are stable, and their formation energies only slightly depend on transition metal M. The η-carbides are the only stable phases for the late [39,40] M 6 C, [41] M 23 C 6 , [42] M 5 C 2 , [43,44] and M 7 C 3 [23,45] ).…”