System titanium-manganese-molybdenum

Structure and stability of Laves phases part II—structure type variations in binary and ternary systems

“…The reason for this behavior is not clear. A plot of the stable polytype as a function of the valence electron number for the series of binary transition metal Laves phases ZrX 2 and TiX 2 (XZNi, Co, Fe, Mn, Cr, V) shows that next to the range of non-stability of Laves phases there is the stability range of the cubic C15 polytype [5]. Obviously, this result cannot be transferred to the ternary systems discussed above.…”

“…The Co-Ti system was one of the first where the occurrence of two different Laves phase modifications was observed [55,56]. Although there were several experimental studies which failed to observe both structure variants [57][58][59], today there is general agreement that the hexagonal C36 and the cubic C15 polytype exist as stable phases in two separate homogeneity ranges [60][61][62][63][64][65][66][67][68][69][70] (see Fig. 3a).…”

“…a sequence C15-C14-C15 is obtained [5]. According to Elliott and Rostoker [5], these periodic variations of the stable polytype in transition metal Laves phase series are correlated with an electronic effect.…”

“…a sequence C15-C14-C15 is obtained [5]. According to Elliott and Rostoker [5], these periodic variations of the stable polytype in transition metal Laves phase series are correlated with an electronic effect. They assume that the increase of the number of valence electrons leads to a transformation of the polytype whenever the Brillouin zone is completely filled up (cf.…”

“…The first group contains binary systems with one Laves phase polytype. This simplest case is excluded from the present paper, because it was already frequently discussed in the literature [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The second group is that of ternary systems with one Laves phase polytype.…”