La transition desordre-ordre A1 → L12 dans les alliages Ni3Mn non-stoechiometriques

Thermodynamic optimization of the Mn–Ni system

“…Recently, Coles [10] reinvestigated the equiatomic region of the Mn-Ni system and stated that it is impossible to have so many stable phases suggested by Tsiuplakis and Kneller [6] at the equiatomic compositon between 480 and 630 8C. In Coles's experimental work [10] all three samples annealed for three months at 500, 525, and 565 8C showed only the lines of the tetragonal CuAuI structure and the behavior below 700 8C in the Ni-rich 0966 [8]. Ding et al [11] also considered that only one phase existed in the equiatomic region between 500 and 650 8C.…”

“…Later, Tsiuplakis and Kneller [6] reinvestigated the Mn-Ni system in detail, in which eight intermetallic compounds Mn 3 Ni, Mn 2 Ni, MnNi(h), MnNi(h 0 ), MnNi(h 00 ), MnNi 2 (x), MnNi 2 (x 0 ), and MnNi 3 were found. In the following years, Adachi and Wayman [7] and Lasserre et al [8] studied the phase diagram of the Mn-Ni system near equiatomic concentration and non-stoichiometric compound MnNi 3 , respectively. Based on the above experimental results especially the phase diagram measured by Tsiuplakis and Kneller [6], the Mn-Ni system was reviewed by Gokcen [9].…”

“…In the present work, the experimental information of the Mn-Ni phase diagram measured by Ding et al [11] between 25 and 70 at.% Ni, Tsiuplakis and Kneller [6] between 0 and 25 at.% Ni, and Lasserre et al [8] at the Nirich region below 700 8C were adopted.…”

“…(a) The Mn-Ni phase diagram calculated by the present thermodynamic description with the experimental data[6,8,11]. (b) Enlarged section of the Mn-Ni phase diagram with experimental data measured by Lasserre et al[8].…”

“…(b) Enlarged section of the Mn-Ni phase diagram with experimental data measured by Lasserre et al[8].…”