Hydrogen pressure dependence of structural changes in C15 Laves phase DyMn2 studied by pressure differential scanning calorimetry

Hydrogen-induced and A-site substitution-dependent structural properties of AB2-type (Ho1−xAx)Co2–hydrogen system (A=Mm and Ti)

“…Since (Ho, Mm) atoms having large negative heat of mixing with hydrogen, the hydrogen atoms can stay more stable in the (2R2M)-sites than in (1R3M)-sites [27,32]. Therefore, it is suggested that the first and the second endothermic peaks are due to hydrogen desorption from the tetrahedral sites surrounded by [1(Ho,Mm) [15][16][17]. In addition, from the XRD and DSC studies of RCo 2 -H systems [4,6,13,[15][16][17], it is concluded that the first exothermic transition is due to the transformation from the crystalline hydride to the amorphous hydride and second exothermic transition is due to the decomposition of amorphous hydride.…”

“…Among these intermetallics, HIA in the Laves phase RM 2 (R = a rare earth metal, M = Fe, Co, Ni and Mn) is particularly interesting and a lot of investigations have been employed to confirm HIA [6][7][8][9][10][11][12]. The formation of amorphous hydrides and decomposition into constituent hydrides greatly depend on the hydrogenation temperature [4,6,9,13], the hydrogen pressure [14][15][16][17] and the type of rare earth or transition metal present in the RM 2 alloy [1][2][3][4]8,10,11,18,19]. Further, there are a few of the investigations on the HIA and decomposition of the pseudobinary and ternary alloys, in which the HIA mainly depends on the substitution of the third element in either of the sites of binary Laves phase RM 2 alloys [20][21][22][23][24][25].…”